Resin composition and foam substrate

Abstract

The present invention relates to a resin composition and a foam substrate, in which the resin composition comprises a first resin and a solvent, in which the viscous flow activation energy of the first resin is 5-40 kJ / mol under the conditions of 120-180 DEG C and a shear rate of 0.05 s <-1 >-1 s <-1 >, the surface tension of the resin composition is 25-70 mN / m, and the viscosity of the first resin is 5-40 kJ / mol under the conditions of 120-180 DEG C and a shear rate of 0.05 s <-1 >-1 s <-1 >. The foam base material comprises a foam core material and a coating coated on the surface of the foam core material, and the coating is obtained by curing the resin composition. The resin composition can completely coat the surface of a foam core material, so that the improvement effects of water absorption and weather resistance of the foam core material are remarkably improved, and a foam base material prepared from the resin composition has excellent environmental tolerance, does not easily absorb water and can be better applied to the technical field of communication.

Description

Technical Field

[0001] The invention relates to the technical field of resin coatings, in particular to a resin composition and a foam substrate. Background Art

[0002] The field of communication technology usually requires materials with low density, good dielectric properties, good stability, and certain strength. Hard foam materials have a large number of gaps and air inside, forming a medium with a low dielectric constant. Combined with the wave-absorbing properties of polymer materials, they can absorb and isolate electromagnetic waves and have good wave-absorbing properties, mechanical properties, and processability. However, due to the characteristics of foam materials, there are a large number of gaps on the surface and inside, resulting in high water absorption and poor weather resistance of foam materials, which limits their further application. Therefore, it is necessary to perform surface coating treatment on the foam material to improve its water absorption and weather resistance.

[0003] At present, traditional technology usually uses resin varnish to coat the surface of foam materials. However, using conventional resin varnish to directly coat the surface of foam materials will result in bubbles, incomplete coating, shrinkage holes, etc., resulting in poor improvement of the water absorption and weather resistance of the foam materials by the surface coating treatment, which cannot meet normal use requirements. Summary of the invention

[0004] Based on this, it is necessary to provide a resin composition and a foam substrate to address the problems existing in the surface coating treatment of the above-mentioned foam material, wherein the resin composition can completely coat the surface of the foam core material, so that the water absorption and weather resistance of the foam core material are significantly improved.

[0005] A resin composition comprises a first resin and a solvent, wherein the viscosity activation energy of the first resin is 120° C.-180° C. and the shear rate is 0.05 s -1 -1s -1 Under the conditions of 5kJ / mol-40kJ / mol, the surface tension of the resin composition is 25mN / m-70mN / m.

[0006] In one embodiment, the functional group contained in the first resin is selected from at least one of epoxy, hydroxyl, carboxyl, amide, amine, aldehyde, carbonyl and vinyl groups;

[0007] And / or, the relative molecular mass of the first resin is 3000-30000;

[0008] And / or, the functional group equivalent of the first resin is 100-1000.

[0009] In one embodiment, the first resin is selected from at least one of epoxy resin, cyanate resin, phenolic resin, benzoxazine resin, maleimide resin, and polyphenylene ether resin.

[0010] In one embodiment, the amount of the solvent used is 30 wt%-160 wt% of the amount of the first resin used.

[0011] In one embodiment, the resin composition further includes a second resin, and the second resin is selected from at least one of modified polyvinyl butyral resin and butadiene-modified epoxy resin.

[0012] In one embodiment, the structural formula of the second resin is as shown in the following formula (1) or formula (2):

[0013]

[0014] Wherein, R1, R2, R3, and R4 are independently selected from at least one of an alkyl group, an olefin group, an ester group, an amine group, an amide group, an alcohol hydroxyl group, an epoxy group, a phenolic hydroxyl group, and a carboxyl group; n1, n2, m1, and m2 are independently selected from 1 to 20; in formula (1), the polarity relationship between R1, R2, and the ketone group is: the polarity of the ketone group is between the polarities of R1 and R2; in formula (2), the polarity relationship between R3, R4, and the ketone group is: the polarity of the ketone group is between the polarities of R3 and R4.

[0015] In one embodiment, the amount of the second resin is 5wt%-30wt% of the amount of the first resin;

[0016] And / or, the density of the second resin is lower than the density of the first resin.

[0017] In one embodiment, the density of the second resin is 0.8 g / cm 3 -1.2g / cm 3 , the density difference between the second resin and the first resin is 0.1-0.4.

[0018] In one embodiment, the resin composition further comprises a filler, and the amount of the filler is 10wt%-60wt% of the amount of the first resin;

[0019] And / or, the resin composition further comprises an auxiliary agent, and the amount of the auxiliary agent is 0.1wt%-5wt% of the amount of the first resin.

[0020] A foam substrate comprises a foam core material and a coating layer covering the surface of the foam core material, wherein the coating layer is obtained by curing the above-mentioned resin composition.

[0021] A method for preparing the foam substrate as described above comprises the following steps: coating the resin composition described above on the surface of the foam core material, and then curing to form a coating to obtain the foam substrate.

[0022] In the resin composition of the present invention, the viscosity change rate of the resin composition at high temperature is controlled by limiting the viscosity flow activation energy of the first resin, so that the flowability of the resin composition in a molten state is moderate, and the surface tension of the resin composition is limited at the same time, so that the resin composition can be completely coated on the surface of the foam core material through the synergistic effect between the viscosity flow activation energy of the first resin and the surface tension of the resin composition, so that the water absorption and weather resistance of the foam core material are significantly improved. Therefore, the foam substrate prepared using the resin composition of the present invention has excellent environmental tolerance, is not easy to absorb water, and can be better applied to the field of communication technology. DETAILED DESCRIPTION

[0023] For ease of understanding of the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific implementation methods or embodiments, and are not intended to limit the present invention. The optional scope of the term "and / or" used herein includes any one of two or more related listed items, and also includes any and all combinations of related listed items, and the combinations include any two related listed items, any more related listed items, or all related listed items.

[0025] After analysis, the reason why the existing resin varnish for surface coating of foam core materials has bubbles, incomplete coating, shrinkage holes, etc., resulting in poor improvement of water absorption and weather resistance of foam core materials is that the viscosity of the existing resin varnish changes rapidly at high temperatures (such as 120℃-180℃), and the reason for the rapid viscosity change rate at high temperatures is mainly that the resin used in it has a high viscosity at 120℃-180℃ and a shear rate of 0.05s -1 -1s -1 This is due to the higher viscosity flow activation energy under the conditions, for example, the viscosity flow activation energy of bisphenol A epoxy resin is about 73.45 kJ / mol, the viscosity flow activation energy of furan epoxy resin is about 85.95 kJ / mol, the viscosity flow activation energy of allyl epoxy resin is about 59.7 kJ / mol, the viscosity flow activation energy of DHPZ epoxy modified resin (ER) is 52 kJ / mol-61 kJ / mol, and the viscosity flow activation energy of modified maleimide resin is 61 kJ / mol-72 kJ / mol.

[0026] However, analysis has shown that directly using a resin with a low viscosity activation energy cannot guarantee that the resin composition can completely cover the surface of the foam core material, resulting in insignificant improvement in the water absorption and weather resistance of the foam core material.

[0027] To this end, the resin composition provided by the present invention comprises a first resin and a solvent, wherein the viscosity flow activation energy of the first resin is 120°C-180°C and the shear rate is 0.05s -1 -1s -1 Under the conditions of 5kJ / mol-40kJ / mol, the surface tension of the resin composition is 25mN / m-70mN / m.

[0028] Therefore, the viscosity change rate of the resin composition at high temperature is controlled by limiting the viscosity activation energy of the first resin, so that the flowability of the resin composition in a molten state is moderate, and at the same time the surface tension of the resin composition is limited, so that through the synergistic effect between the viscosity activation energy of the first resin and the surface tension of the resin composition, the resin composition can be completely coated on the surface of the foam core material, which significantly improves the water absorption and weather resistance of the foam core material. Therefore, the foam substrate prepared using the resin composition of the present invention has excellent environmental tolerance, is not easy to absorb water, and can be better applied to the field of communication technology.

[0029] It should be noted that in the present invention, the first resin is heated at 120°C-180°C and the shear rate is 0.05s -1 The test method of the viscosity flow activation energy under the conditions of is as follows: the first resin to be tested is placed in a 60℃-70℃ oven for 48h to remove moisture, and then a rheological experiment is carried out on a RH-2000 double-tube extrusion capillary rheometer, wherein the capillary die diameter is 1.0mm, the aspect ratio is 16:1, and the first resin is tested at 120-180℃ for 0.05s -1 Activation energy of viscous flow at shear rate.

[0030] Taking into account the factors affecting the surface tension of the resin composition, such as the type of the first resin, the relative molecular mass of the first resin, etc., in one embodiment, the functional group contained in the first resin is selected from at least one of epoxy, hydroxyl, carboxyl, amide, amine, aldehyde, carbonyl, and vinyl, and / or the relative molecular mass of the first resin is 3000-30000, preferably 5000-20000.

[0031] Such an arrangement can better control the surface tension of the first resin, and further better control the surface tension of the resin composition to 25mN / m-70mN / m, so that the resin composition can be better and completely coated on the surface of the foam core material, thereby better improving the water absorption and weather resistance of the foam core material.

[0032] Furthermore, the first resin is selected from at least one of epoxy resin, cyanate resin, phenolic resin, benzoxazine resin, maleimide resin and polyphenylene ether resin.

[0033] Specifically, the epoxy resin can be a polymethacrylate modified epoxy resin (at 120°C-180°C and a shear rate of 0.05s -1 -1s -1 The viscosity flow activation energy under the conditions is about 28kJ / mol), ester type epoxy resin (at 120℃-180℃, shear rate 0.05s -1 -1s -1 The viscous flow activation energy under the conditions is about 27 kJ / mol).

[0034] The cyanate resin may be an isocyanate-terminated polybutadiene (at 120°C-180°C and a shear rate of 0.05s -1 -1s -1 The viscosity flow activation energy under the conditions is about 22kJ / mol), bisphenol A cyanate prepolymer (at 120℃-180℃, shear rate of 0.05s -1 -1s -1 The viscous flow activation energy under the conditions is about 31 kJ / mol).

[0035] The phenolic resin may be a linear phenolic resin (at 120°C-180°C and a shear rate of 0.05s -1 -1s -1 The viscosity flow activation energy under the conditions is about 35kJ / mol), phenol linear phenolic resin (at 120℃-180℃, shear rate of 0.05s -1 -1s -1 The viscous flow activation energy under the conditions is about 38 kJ / mol).

[0036] The benzoxazine resin may be a bisphenol diamine type benzoxazine resin (at 120°C-180°C and a shear rate of 0.05s -1 -1s -1 The viscous flow activation energy under the conditions is about 33 kJ / mol).

[0037] The maleimide resin can be polymaleimide (at 120°C-180°C and a shear rate of 0.05s -1 -1s -1The viscosity flow activation energy under the conditions is about 35kJ / mol), multi-maleimide prepolymer (at 120℃-180℃, shear rate of 0.05s -1 -1s -1 The viscous flow activation energy under the conditions is about 36 kJ / mol).

[0038] The polyphenylene ether resin can be a vinyl benzyl terminal modified polyphenylene ether (at 120°C-180°C and a shear rate of 0.05s -1 -1s -1 The viscous flow activation energy under the conditions is about 27 kJ / mol).

[0039] More preferably,

[0040] Meanwhile, the functional group equivalent of the first resin is 100-1000, preferably, the functional group equivalent of the first resin is 150-500. Such arrangement can further control the surface tension of the first resin, thereby better controlling the surface tension of the resin composition, thereby further improving the completeness of the foam core material coating and improving the coating flatness of the foam core material surface.

[0041] In another embodiment, the first resin may also be a combination of bisphenol diamine type benzoxazine, polymaleimide prepolymer, and vinyl benzyl terminal modified polyphenylene ether, and the multiple resins cooperate to improve the coating integrity of the foam core surface.

[0042] In one embodiment, the amount of the solvent is 30wt%-160wt% of the amount of the first resin. This configuration can better control the surface tension of the resin composition, thereby allowing the resin composition to more completely cover the surface of the foam core material.

[0043] Furthermore, the solvent is selected from at least one of butanone, acetone, xylene and toluene.

[0044] In one embodiment, the resin composition further includes a second resin, and the second resin is selected from at least one of modified polyvinyl butyral resin and butadiene modified epoxy resin. Such an arrangement can further improve the flatness of the surface of the foam core material coated with the resin composition.

[0045] Preferably, the structural formula of the second resin is as shown in the following formula (1) or formula (2):

[0046]

[0047] Wherein, R1, R2, R3, and R4 are independently selected from at least one of an alkyl group, an olefin group, an ester group, an amine group, an amide group, an alcoholic hydroxyl group, an epoxy group, a phenolic hydroxyl group, and a carboxyl group, wherein the polarity relationship of the alkyl group, the olefin group, the ester group, the amine group, the amide group, the alcoholic hydroxyl group, the epoxy group, the phenolic hydroxyl group, and the carboxyl group is: the polarity of the alkyl group, the olefin group, and the ester group is less than the polarity of the ketone group, and the polarity of the amine group, the amide group, the alcoholic hydroxyl group, the epoxy group, the phenolic hydroxyl group, and the carboxyl group is greater than the polarity of the ketone group, n1, n2, m1, and m2 are independently selected from 1-20, in formula (1), the polarity relationship between R1, R2, and the ketone group is: the polarity of the ketone group is between the polarities of R1 and R2, and in formula (2), the polarity relationship between R3, R4, and the ketone group is: the polarity of the ketone group is between the polarities of R3 and R4.

[0048] More preferably, the structural formula of the second resin is as shown in the following formula (3) or formula (4):

[0049]

[0050] Wherein, n1, n2, m1 and m2 are independently selected from 1-20, preferably, n1, n2, m1 and m2 are independently selected from 1-10.

[0051] With such a configuration, the surface tension of the resin composition can be better controlled through the group polarity of the second resin, making it easier for the resin composition to form a film of uniform thickness on the surface of the foam core material, reducing the thickness extremes, thereby improving the thickness uniformity of the resin composition after coating the surface of the foam core material, and further improving the integrity and apparent smoothness of the coating.

[0052] It should be noted that in order to make it easier for the resin composition to form a thin film on the surface of the foam core material, the present invention defines the polarity relationship of different functional groups in the structural formula of the second resin based on the adsorption effect of the molecule, that is, the end with a larger polarity tends to extend into the solvent, and the end with a smaller polarity tends to contact the air, taking the keto group, a functional group with an intermediate polarity, as a reference benchmark, wherein, when the structural formula of the second resin is formula (1), the polarity relationship between R1, R2 and the keto group in formula (1) is: the polarity of the keto group is between the polarities of R1 and R2, specifically, R1 < keto group < R2 or R2 < keto group < R1; when the structural formula of the second resin is formula (2), the polarity relationship between R3, R4 and the keto group in formula (2) is: the polarity of the keto group is between the polarities of R3 and R4, specifically, R3 < keto group < R4 or R4 < keto group < R3. Such an arrangement allows a larger polarity difference to be formed between R1 and R2 in formula (1), or a larger polarity difference to be formed between R3 and R4 in formula (2), so that when the second resin is formed into a film, the molecular arrangement is more regular and the effect is better, thereby allowing the resin composition to form a thin film with uniform thickness on the surface of the foam core material, thereby improving the flatness after coating.

[0053] Furthermore, the amount of the second resin is 5wt%-30wt% of the amount of the first resin. This arrangement can better ensure the flatness of the resin composition after coating.

[0054] In one embodiment, the density of the second resin is less than that of the first resin. This arrangement allows the second resin to slightly separate from the first resin when not reacted, and through the surface adsorption effect, the groups with large polarity in the second resin tend to be incorporated into the first resin, and the groups with small polarity tend to be separated from the first resin, so the second resin can float on the surface of the resin composition to form a film with uniform thickness, thereby improving the flatness of the surface of the foam core material coated with the resin composition.

[0055] In one embodiment, the density of the second resin is 0.8 g / cm 3 -1.2g / cm 3 The density difference between the second resin and the first resin is 0.1-0.4. Such an arrangement can better ensure the uniformity of the coating thickness of the resin composition and improve the apparent smoothness of the foam core material coated with the resin composition.

[0056] In one embodiment, the resin composition further comprises a filler, and the amount of the filler is 10wt%-60wt% of the amount of the first resin. Such an arrangement can help control the surface tension of the resin composition, disperse the internal stress of the resin composition after curing, improve the orange peel phenomenon, reduce the thickness difference, and improve the uniformity of the thickness of the resin composition covering the surface of the foam core material.

[0057] Preferably, the filler is selected from at least one of silicon micropowder, alumina, talcum powder and titanium dioxide. Further, the filler can be treated with a coupling agent, and the coupling agent is selected from at least one of a silane coupling agent and a carbonate coupling agent.

[0058] In one embodiment, the resin composition further comprises an auxiliary agent, and the amount of the auxiliary agent is 0.1wt%-5wt% of the amount of the first resin. This arrangement can adjust the reaction speed of the resin composition, improve the orange peel phenomenon, and thus reduce the thickness difference of the foam core material coated with the resin composition.

[0059] Furthermore, the auxiliary agent may be a curing accelerator, and the curing accelerator is selected from at least one of a phosphorus-based curing accelerator, an amine-based curing accelerator, an imidazole-based curing accelerator, a guanidine-based curing accelerator, and a metal-based curing accelerator.

[0060] In one embodiment, the method for preparing the resin composition comprises: adding a first resin, a second resin and a filler into a solvent, and stirring them uniformly to prepare a mixed solution, and then adding an auxiliary agent and continuing stirring to obtain the resin composition.

[0061] Meanwhile, the present invention also provides a foam substrate, comprising a foam core material and a coating layer coated on the surface of the foam core material, wherein the coating layer is obtained by curing the resin composition.

[0062] Since the resin composition used can completely cover the surface of the foam core material to form a coating with complete coating, uniform thickness and smooth surface, the foam substrate has excellent environmental tolerance and is not easy to absorb water, and can be better applied in the field of communication technology.

[0063] In one embodiment, the foam core material may be a polymethacrylimide foam core material, a polyetherketone foam core material, a polyaryletherketone foam core material, a polystyrene foam core material, a polyurethane foam core material, a polyvinyl chloride foam core material, or an acrylate foam core material.

[0064] In one embodiment, the present invention also provides a method for preparing a foam substrate, comprising the following steps: coating the resin composition on the surface of a foam core material, and then curing to form a coating, wherein the curing temperature is 120°C-200°C, and the curing time is 1h-6h, to obtain a foam substrate.

[0065] In one embodiment, before coating the resin composition on the surface of the foam core material, the surface of the foam core material is cleaned with anhydrous ethanol and then dried, wherein the drying temperature is 80° C.-100° C. and the drying time is 1 h-3 h.

[0066] In one embodiment, the resin composition is coated on the surface of the foam core material by coating, spraying, etc. and allowed to stand for 2 minutes to 10 minutes.

[0067] Hereinafter, the resin composition and the foam substrate will be further described through the following specific examples.

[0068] It should be noted that the raw materials and reagent components involved in the present invention can all be purchased from the market.

[0069] At the same time, the performance parameters of each raw material in the embodiments and comparative examples of the present invention are as follows:

[0070] Polymethacrylate modified epoxy resin: at 120℃-180℃, shear rate of 0.05s -1 -1s -1 The viscous flow activation energy under the conditions is about 28 kJ / mol, the relative molecular mass is 10000, the functional group equivalent is 110, and the density is 1.15 g / cm3 , brand number 705314, manufacturer Merck Life Sciences;

[0071] Four-arm-polyethylene glycol-epoxy resin: at 120℃-180℃, shear rate 0.05s -1 -1s -1 The viscous flow activation energy under the conditions is 4.9 kJ / mol, the relative molecular mass is 3400, the functional group equivalent is 850, and the density is 1.2 g / cm 3 , brand name is universal, manufacturer is Xi'an Kaixin;

[0072] Bisphenol A cyanate prepolymer: at 120℃-180℃, shear rate of 0.05s -1 -1s -1 The viscous flow activation energy under the conditions is about 31 kJ / mol, the relative molecular mass is 6500, the functional group equivalent is 140, and the density is 1.26 g / cm 3 , brand name C01PS, manufacturer Yangzhou Tianqi;

[0073] Phenol novolac resin: at 120℃-180℃, shear rate of 0.05s -1 -1s -1 The viscous flow activation energy under the conditions is about 38 kJ / mol, the relative molecular mass is 3800, the functional group equivalent is 106, and the density is 1.17 g / cm 3 , brand DFE312, manufacturer Sichuan Dongcai;

[0074] Bisphenol diamine type benzoxazine resin: at 120℃-180℃, shear rate of 0.05s -1 -1s -1 The viscous flow activation energy under the conditions is about 33 kJ / mol, the relative molecular mass is 3200, the functional group equivalent is 190, and the density is 1.21 g / cm 3 , brand DFE149, manufacturer Sichuan Dongcai;

[0075] Polymaleimide prepolymer: at 120℃-180℃, shear rate of 0.05s -1 -1s -1 The viscous flow activation energy under the conditions is about 36 kJ / mol, the relative molecular mass is 6000, the functional group equivalent is 160, and the density is 1.2 g / cm 3 , brand DFE960B, manufacturer Sichuan Dongcai;

[0076] Biphenyl polymaleimide resin: at 120℃-180℃, shear rate of 0.05s -1 -1s -1The viscous flow activation energy under the conditions is 72 kJ / mol, the relative molecular mass is 3200, the functional group equivalent is 360, and the density is 1.2 g / cm 3 , brand DFE958, manufacturer Sichuan Dongcai;

[0077] Vinyl benzyl terminal modified polyphenylene ether resin: at 120℃-180℃, shear rate of 0.05s -1 -1s -1 The viscous flow activation energy under the conditions is about 27 kJ / mol, the relative molecular mass is 3600, the functional group equivalent is 900, and the density is 1.24 g / cm 3 , brand name OPE-2St, manufacturer Mitsubishi Gas;

[0078] Modified polyvinyl butyral resin 1: density 1.03g / cm 3 , brand name B16H, manufacturer Kuraray;

[0079] Modified polyvinyl butyral resin 2: density 1.05g / cm 3 , brand name B75H, manufacturer Kuraray;

[0080] Modified polyvinyl butyral resin 3: density 1.05g / cm 3 , brand name B60H, manufacturer Kuraray;

[0081] Modified polybutadiene resin: density 1.05g / cm 3 , brand GQ-1000, manufacturer: Japan Soda;

[0082] Butadiene modified epoxy resin 1: density 1.05g / cm 3 , brand JP-100, manufacturer Japan Soda;

[0083] Butadiene modified epoxy resin 2: density 1.20g / cm 3 , brand EPP-175, manufacturer complex high-tech materials.

[0084] Example 1

[0085] According to parts by weight, 50 parts by weight of a polymethacrylate-modified epoxy resin (first resin) was dissolved in 66.7 parts by weight of a butanone solvent to obtain a resin composition.

[0086] A 300 mm×300 mm×2 mm polymethacrylimide foam core material was taken, and the surface of the polymethacrylimide foam core material was cleaned with anhydrous ethanol, and then placed in a 90° C. oven to dry for 2 h to obtain a clean polymethacrylimide foam core material.

[0087] The resin composition obtained above was evenly sprayed on the surface of the clean polymethacrylimide foam core material using a spray gun, and after standing for 5 minutes, it was placed in a 160° C. oven for curing for 3 hours to form a coating, thereby obtaining a foam substrate.

[0088] Example 2

[0089] The only difference between Example 2 and Example 1 is that in Example 2, 50 parts by weight of bisphenol A cyanate prepolymer (first resin) and 25 parts by weight of SiO2 filler are dissolved in 66.7 parts by weight of butanone solvent to obtain a resin composition.

[0090] This example adopts the method for preparing the foam substrate in Example 1 to prepare the foam substrate.

[0091] Example 3

[0092] The only difference between Example 3 and Example 1 is that in Example 3, 50 parts by weight of phenol linear phenolic resin (first resin) and 25 parts by weight of SiO2 filler are dissolved in 66.7 parts by weight of butanone solvent, and stirred evenly to obtain a mixed solution, and then 0.1 parts by weight of imidazole curing accelerator are added and mixed evenly to obtain a resin composition.

[0093] This example adopts the method for preparing the foam substrate in Example 1 to prepare the foam substrate.

[0094] Example 4

[0095] The only difference between Example 4 and Example 1 is that in Example 4, 15 parts by weight of modified polyvinyl butyral resin 1 (second resin) is further added to the resin composition and dissolved in butanone solvent, and the rest are the same to obtain a resin composition.

[0096] This example adopts the method for preparing the foam substrate in Example 1 to prepare the foam substrate.

[0097] Example 5

[0098] The only difference between Example 5 and Example 2 is that in Example 5, 2.5 parts by weight of modified polyvinyl butyral resin 1 (second resin) is further added to the resin composition and dissolved in butanone solvent, and the rest are the same to obtain a resin composition.

[0099] This example adopts the method for preparing the foam substrate in Example 1 to prepare the foam substrate.

[0100] Example 6

[0101] The only difference between Example 6 and Example 3 is that in Example 6, 10 parts by weight of modified polyvinyl butyral resin 1 (second resin) is further added and dissolved in butanone solvent, and the rest are the same to obtain a resin composition.

[0102] This example adopts the method for preparing the foam substrate in Example 1 to prepare the foam substrate.

[0103] Example 7

[0104] The only difference between Example 7 and Example 1 is that in Example 7, 20 parts by weight of bisphenol diamine type benzoxazine resin, 20 parts by weight of polymaleimide prepolymer and 10 parts by weight of vinyl benzyl terminal modified polyphenylene ether resin are used as the first resin in the preparation of the resin composition, and the rest are the same to obtain a resin composition.

[0105] This example adopts the method for preparing the foam substrate in Example 1 to prepare the foam substrate.

[0106] Example 8

[0107] The only difference between Example 8 and Example 6 is that in Example 8, in preparing the resin composition, the second resin structure is as shown in formula (3), n1 is 16, n2 is 19, that is, modified polyvinyl butyral resin 2, and the rest are the same to obtain a resin composition.

[0108] This example adopts the method for preparing the foam substrate in Example 1 to prepare the foam substrate.

[0109] Example 9

[0110] The only difference between Example 9 and Example 6 is that in Example 9, in preparing the resin composition, the structural formula of the second resin is as shown in formula (4), m1 is 7, m2 is 16, that is, modified butadiene-modified epoxy resin 1, and the rest are the same to obtain a resin composition.

[0111] This example adopts the method for preparing the foam substrate in Example 1 to prepare the foam substrate.

[0112] Example 10

[0113] The only difference between Example 10 and Example 6 is that in Example 10, in preparing the resin composition, the structural formula of the second resin is as shown in formula (1), R1 is propyl, R2 is vinyl, n1 is 9, n2 is 15, that is, modified polyvinyl butyral resin 3, and the rest are the same to obtain a resin composition.

[0114] This example adopts the method for preparing the foam substrate in Example 1 to prepare the foam substrate.

[0115] Embodiment 11

[0116] The only difference between Example 11 and Example 6 is that in Example 11, in preparing the resin composition, the structural formula of the second resin is as shown in Formula (2), R3 is a hydroxyl group, R4 is a carboxyl group, m1 is 14, and m2 is 15, that is, a modified polybutadiene resin, and the rest are the same to obtain a resin composition.

[0117] This example adopts the method for preparing the foam substrate in Example 1 to prepare the foam substrate.

[0118] Example 12

[0119] The only difference between Example 12 and Example 6 is that in Example 12, butadiene-modified epoxy resin 2 is used to replace modified polyvinyl butyral resin as the second resin in the preparation of the resin composition, and the rest are the same to obtain a resin composition.

[0120] This example adopts the method for preparing the foam substrate in Example 1 to prepare the foam substrate.

[0121] Embodiment 13

[0122] The only difference between Example 13 and Example 6 is that in Example 13, the weight portion of the SiO2 filler is 4, the weight portion of the imidazole curing accelerator is 0.04, and the rest are the same, thereby obtaining a resin composition.

[0123] This example adopts the method for preparing the foam substrate in Example 1 to prepare the foam substrate.

[0124] Comparative Example 1

[0125] The only difference between Comparative Example 1 and Example 6 is that in Comparative Example 1, biphenyl polymaleimide resin is used as the first resin, and the rest are the same to obtain a resin composition.

[0126] In this comparative example, the foam substrate was prepared by the method for preparing the foam substrate in Example 1.

[0127] Comparative Example 2

[0128] The only difference between Comparative Example 2 and Example 6 is that in Comparative Example 2, four-arm-polyethylene glycol-epoxy resin is used as the first resin, and the rest are the same to obtain a resin composition.

[0129] In this comparative example, the foam substrate was prepared by the method for preparing the foam substrate in Example 1.

[0130] Comparative Example 3

[0131] Compared with Example 6, Comparative Example 3 differs only in that, in Comparative Example 3, 50 parts by weight of polymethacrylate modified epoxy resin as the first resin, 15 parts by weight of modified polyvinyl butyral resin 1 as the second resin, and 25 parts by weight of SiO2 filler are dissolved in 14 parts by weight of butanone solvent, and stirred evenly to obtain a mixed solution, and then 0.1 parts by weight of imidazole curing accelerator are added and mixed evenly to obtain a resin composition.

[0132] In this comparative example, the foam substrate was prepared by the method for preparing the foam substrate in Example 1.

[0133] Comparative Example 4

[0134] Compared with Example 6, Comparative Example 4 is different only in that, in Comparative Example 4, 40 parts by weight of polymethacrylate modified epoxy resin as the first resin, 10 parts by weight of modified polyvinyl butyral resin 1 as the second resin, and 25 parts by weight of SiO2 filler are dissolved in 65 parts by weight of butanone solvent, and stirred evenly to obtain a mixed solution, and then 0.1 parts by weight of imidazole curing accelerator are added and mixed evenly to obtain a resin composition.

[0135] In this comparative example, the foam substrate was prepared by the method for preparing the foam substrate in Example 1.

[0136] In the present invention, water absorption and weather resistance are used to characterize the integrity of the coating of the foam core material surface by the resin composition, and flatness is used to characterize the flatness of the coating of the foam core material surface by the resin composition.

[0137] The surface tension of the resin compositions of Examples 1-13 and Comparative Examples 1-4 was tested. At the same time, the water absorption, weather resistance and flatness of the foam substrates prepared in Examples 1-13 and Comparative Examples 1-4 were tested. The specific test contents and standards are shown below. The test results are shown in Tables 1 and 2, wherein the test parameter conditions of each embodiment and comparative example are the same.

[0138] Surface tension: The test method is the hanging drop method. Specifically, the resin composition is squeezed out from a capillary dropper using a contact angle tester, the profile of the droplet when in equilibrium is recorded, and the profile is brought into the Bashforth-Adams (axisymmetric liquid surface) equation to determine the surface tension of the resin composition by the hanging drop method;

[0139] Water absorption: Test method is in accordance with GB / T4722-2017 9.2;

[0140] Weather resistance: The test method is as follows: the foam core material to be tested is treated according to GB / T2423.50 and the test method is according to GB / T8813-2008;

[0141] Flatness: The test method is as follows: select a 1mm×1mm test plane through a confocal microscope, measure the height deviation within the plane, and obtain the flatness data.

[0142] Table 1

[0143]

[0144] Table 2

[0145]

[0146]

[0147] It can be seen from the data in Tables 1-2 that the resin composition of the present invention can be completely coated on the surface of the foam core material, so that the water absorption and weather resistance of the foam core material are significantly improved. Furthermore, the foam substrate prepared using the resin composition of the present invention has excellent environmental tolerance, is not easy to absorb water, and can be better applied in the field of communication technology.

[0148] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0149] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A resin composition, characterized in that The invention comprises a first resin and a solvent, wherein the viscosity activation energy of the first resin is 120°C-180°C and the shear rate is 0.05s -1 -1s -1 Under the conditions of 5kJ / mol-40kJ / mol, the surface tension of the resin composition is 25mN / m-70mN / m.

2. The resin composition according to claim 1, characterized in that The functional group contained in the first resin is at least one selected from epoxy, hydroxyl, carboxyl, amide, amine, aldehyde, carbonyl and vinyl groups; And / or, the relative molecular mass of the first resin is 3000-30000; And / or, the functional group equivalent of the first resin is 100-1000.

3. The resin composition according to claim 2, characterized in that The first resin is selected from at least one of epoxy resin, cyanate resin, phenolic resin, benzoxazine resin, maleimide resin and polyphenylene ether resin.

4. The resin composition according to claim 1, characterized in that The amount of the solvent used is 30 wt% to 160 wt% of the amount of the first resin used.

5. The resin composition according to claim 1, characterized in that The resin composition further includes a second resin, and the second resin is selected from at least one of a modified polyvinyl butyral resin and a butadiene-modified epoxy resin.

6. The resin composition according to claim 5, characterized in that The structural formula of the second resin is shown in the following formula (1) or formula (2): Wherein, R1, R2, R3, and R4 are independently selected from at least one of an alkyl group, an olefin group, an ester group, an amine group, an amide group, an alcohol hydroxyl group, an epoxy group, a phenolic hydroxyl group, and a carboxyl group; n1, n2, m1, and m2 are independently selected from 1 to 20; in formula (1), the polarity relationship between R1, R2, and the ketone group is: the polarity of the ketone group is between the polarities of R1 and R2; in formula (2), the polarity relationship between R3, R4, and the ketone group is: the polarity of the ketone group is between the polarities of R3 and R4.

7. The resin composition according to claim 5, characterized in that The amount of the second resin is 5wt%-30wt% of the amount of the first resin; And / or, the density of the second resin is lower than the density of the first resin.

8. The resin composition according to claim 7, characterized in that The density of the second resin is 0.8 g / cm 3 -1.2g / cm 3 , the density difference between the second resin and the first resin is 0.1-0.

4.

9. The resin composition according to any one of claims 1 to 8, characterized in that The resin composition further comprises a filler, wherein the amount of the filler is 10wt%-60wt% of the amount of the first resin; And / or, the resin composition further comprises an auxiliary agent, and the amount of the auxiliary agent is 0.1wt%-5wt% of the amount of the first resin.

10. A foam substrate, characterized in that: It comprises a foam core material and a coating layer covering the surface of the foam core material, wherein the coating layer is obtained by curing the resin composition according to any one of claims 1 to 9.

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