CN115418186A - Shielding case with waterproof function - Google Patents
Shielding case with waterproof function Download PDFInfo
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- CN115418186A CN115418186A CN202210849877.2A CN202210849877A CN115418186A CN 115418186 A CN115418186 A CN 115418186A CN 202210849877 A CN202210849877 A CN 202210849877A CN 115418186 A CN115418186 A CN 115418186A
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- Prior art keywords
- waterproof
- shielding case
- temperature
- glue
- sbs
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- 239000000839 emulsion Substances 0.000 claims abstract description 46
- 239000012790 adhesive layer Substances 0.000 claims abstract description 37
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims abstract description 36
- 239000000203 mixture Substances 0.000 claims abstract description 26
- HDETVIAMQNTONT-UHFFFAOYSA-N C[SiH2]O.[Na] Chemical compound C[SiH2]O.[Na] HDETVIAMQNTONT-UHFFFAOYSA-N 0.000 claims abstract description 13
- 239000002994 raw material Substances 0.000 claims abstract description 10
- 229920006132 styrene block copolymer Polymers 0.000 claims abstract description 9
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 7
- 239000003292 glue Substances 0.000 claims description 58
- 239000010410 layer Substances 0.000 claims description 47
- 238000006243 chemical reaction Methods 0.000 claims description 27
- 238000002360 preparation method Methods 0.000 claims description 21
- 239000000853 adhesive Substances 0.000 claims description 18
- 230000001070 adhesive effect Effects 0.000 claims description 18
- 238000002156 mixing Methods 0.000 claims description 18
- 238000010438 heat treatment Methods 0.000 claims description 17
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 claims description 14
- 238000003756 stirring Methods 0.000 claims description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 14
- 238000002844 melting Methods 0.000 claims description 10
- 230000008018 melting Effects 0.000 claims description 10
- CQEYYJKEWSMYFG-UHFFFAOYSA-N butyl acrylate Chemical compound CCCCOC(=O)C=C CQEYYJKEWSMYFG-UHFFFAOYSA-N 0.000 claims description 9
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 claims description 8
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims description 8
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 claims description 8
- 239000012752 auxiliary agent Substances 0.000 claims description 8
- 239000011259 mixed solution Substances 0.000 claims description 8
- 239000007788 liquid Substances 0.000 claims description 7
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 claims description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 6
- 239000002861 polymer material Substances 0.000 claims description 6
- 229910052710 silicon Inorganic materials 0.000 claims description 6
- 239000010703 silicon Substances 0.000 claims description 6
- GNSFRPWPOGYVLO-UHFFFAOYSA-N 3-hydroxypropyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCCCO GNSFRPWPOGYVLO-UHFFFAOYSA-N 0.000 claims description 5
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 claims description 4
- 239000004642 Polyimide Substances 0.000 claims description 4
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 claims description 4
- 229920001807 Urea-formaldehyde Polymers 0.000 claims description 4
- GZCGUPFRVQAUEE-SLPGGIOYSA-N aldehydo-D-glucose Chemical compound OC[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C=O GZCGUPFRVQAUEE-SLPGGIOYSA-N 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 4
- GVGUFUZHNYFZLC-UHFFFAOYSA-N dodecyl benzenesulfonate;sodium Chemical compound [Na].CCCCCCCCCCCCOS(=O)(=O)C1=CC=CC=C1 GVGUFUZHNYFZLC-UHFFFAOYSA-N 0.000 claims description 4
- 239000003995 emulsifying agent Substances 0.000 claims description 4
- 238000001914 filtration Methods 0.000 claims description 4
- 239000005011 phenolic resin Substances 0.000 claims description 4
- 229920001568 phenolic resin Polymers 0.000 claims description 4
- 229920001721 polyimide Polymers 0.000 claims description 4
- 238000005096 rolling process Methods 0.000 claims description 4
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims description 4
- 235000017557 sodium bicarbonate Nutrition 0.000 claims description 4
- 229940080264 sodium dodecylbenzenesulfonate Drugs 0.000 claims description 4
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 claims description 4
- 229920006335 epoxy glue Polymers 0.000 claims description 3
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 claims description 2
- 230000000694 effects Effects 0.000 abstract description 17
- 238000004078 waterproofing Methods 0.000 abstract description 4
- 230000000052 comparative effect Effects 0.000 description 12
- GBPOWOIWSYUZMH-UHFFFAOYSA-N sodium;trihydroxy(methyl)silane Chemical compound [Na+].C[Si](O)(O)O GBPOWOIWSYUZMH-UHFFFAOYSA-N 0.000 description 9
- 239000000178 monomer Substances 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- 230000002940 repellent Effects 0.000 description 7
- 239000005871 repellent Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 239000004816 latex Substances 0.000 description 5
- 229920000126 latex Polymers 0.000 description 5
- 239000002245 particle Substances 0.000 description 4
- -1 polyphenylene Polymers 0.000 description 4
- JQQMGDZAJQTYQC-UHFFFAOYSA-N [Na+].C[SiH2][O-] Chemical compound [Na+].C[SiH2][O-] JQQMGDZAJQTYQC-UHFFFAOYSA-N 0.000 description 3
- 230000032683 aging Effects 0.000 description 3
- 229920006332 epoxy adhesive Polymers 0.000 description 3
- 229920002857 polybutadiene Polymers 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- RRHGJUQNOFWUDK-UHFFFAOYSA-N Isoprene Chemical compound CC(=C)C=C RRHGJUQNOFWUDK-UHFFFAOYSA-N 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 239000002585 base Substances 0.000 description 2
- 238000013329 compounding Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 238000006116 polymerization reaction Methods 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- 239000005060 rubber Substances 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 239000005062 Polybutadiene Substances 0.000 description 1
- 229920000265 Polyparaphenylene Polymers 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229920001400 block copolymer Polymers 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 238000006482 condensation reaction Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000000693 micelle Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 238000005191 phase separation Methods 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 230000007096 poisonous effect Effects 0.000 description 1
- 229920001195 polyisoprene Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 230000001743 silencing effect Effects 0.000 description 1
- 239000013464 silicone adhesive Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
- 230000002459 sustained effect Effects 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 229920000428 triblock copolymer Polymers 0.000 description 1
- 239000004636 vulcanized rubber Substances 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J153/00—Adhesives based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Adhesives based on derivatives of such polymers
- C09J153/02—Vinyl aromatic monomers and conjugated dienes
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
- C09J11/02—Non-macromolecular additives
- C09J11/06—Non-macromolecular additives organic
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
- C09J11/08—Macromolecular additives
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K9/00—Screening of apparatus or components against electric or magnetic fields
- H05K9/0007—Casings
- H05K9/002—Casings with localised screening
- H05K9/0022—Casings with localised screening of components mounted on printed circuit boards [PCB]
- H05K9/0024—Shield cases mounted on a PCB, e.g. cans or caps or conformal shields
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
- C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Sealing Material Composition (AREA)
Abstract
The application relates to the waterproof field of components and parts, especially relates to a can take shield cover of waterproof function. The shielding case with the waterproof function comprises a shielding case body and a waterproof adhesive layer arranged in the shielding case body; the waterproof adhesive layer is prepared from the following raw materials in parts by weight: 50-70 parts of styrene block copolymer and 20-40 parts of waterproofing agent; the styrene block copolymer is a mixture of SIS and SBS, and the mass ratio of SIS to SBS is (3-5): 1; the waterproof agent is a mixture of sodium methyl silanol and acrylic emulsion, and the mass ratio of the sodium methyl silanol to the acrylic emulsion is (1-3): 1. the shield cover that this application formed has the shielding to components and parts and adds waterproof effect, has improved the water-proof effects of components and parts.
Description
Technical Field
The application relates to the field of component waterproofing, especially, relate to a can take shield cover of waterproof function.
Background
The PCB board usually needs to adopt the shield cover to waterproof the components and parts in the space limited by the shield cover and the board body, and the traditional process is to waterproof the components and parts first and then weld the shield cover. The waterproof layer can be destroyed by the operation, so that the waterproof property of the component is influenced.
In view of the above problems, the inventors of the present invention have considered that improving the water resistance of a component is important for the development of the component.
Disclosure of Invention
In order to improve the waterproof nature of components and parts, this application provides a can take shield cover of waterproof function.
The application provides a can take shield cover of waterproof function adopts following technical scheme:
a shielding case with a waterproof function comprises a shielding case body and a waterproof adhesive layer arranged in the shielding case body; the waterproof adhesive layer is prepared from the following raw materials in parts by weight: 60-70 parts of styrene block copolymer and 20-30 parts of waterproof agent; the styrene block copolymer is a mixture of SIS and SBS, and the mass ratio of SIS to SBS is (3-5): 1; the waterproof agent is a mixture of sodium methyl silanol and acrylic emulsion, and the mass ratio of the sodium methyl silanol to the acrylic emulsion is (1-3): 1.
by adopting the technical scheme, the SIS is a triblock copolymer consisting of styrene and isoprene. The soft rubber chain segment of polyisoprene isolated from each other is arranged in the middle, the hard plastic chain segments of the polyphenylene are arranged on two sides, the rubber has the performance of vulcanized rubber at room temperature, and has the advantages of plasticity at high temperature, good elasticity and bonding strength, low temperature resistance, good solubility resistance, low solution viscosity, fast curing and the like. SBS is polystyrene-polybutadiene-styrene ternary block copolymer, in which the polystyrene chain segment and the polybutadiene chain segment are obviously in two-phase structure, mutually incompatible and in phase separation state. SBS has excellent tensile strength, elasticity and electrical property, small permanent deformation, good flexibility and rebound resilience and large surface friction. The ozone, oxygen and ultraviolet irradiation resistance is similar to that of styrene butadiene rubber. Because the main chain of the modified polybutadiene rubber contains unsaturated double bonds, the aging resistance of SBS is poor, and under the oxidation condition of high temperature air, the butadiene block can be cross-linked, so that the hardness and viscosity of the modified polybutadiene rubber are increased. When the SIS and the SBS are compounded for use, the SBS can make up the viscosity of the SIS, and the SIS can improve the aging resistance of the SBS, so that the obtained glue layer has good elasticity, high and low temperature resistance and curing rate.
More importantly, sodium methyl silanol reacts with air on a base material to be condensed into a high molecular compound, namely, the reticular organic silicon resin film has hydrophobicity, but the reticular organic silicon resin film can only exist under strong alkali; and acrylic emulsion has good waterproof performance, and it is flammable, explosive, poisonous etc. shortcoming not only to have overcome oily acrylic ester, and more importantly, this application combines sodium methylsiliconate and acrylic emulsion to use, finds that acrylic emulsion can not destroyed by strong alkaline sodium methylsiliconate, leads to the problem that water-proof effects reduces. Meanwhile, by compounding the sodium methylsiliconate and the acrylic emulsion, the sodium methylsiliconate and the acrylic emulsion have a synergistic effect, so that the waterproof effect of the adhesive layer is further improved.
To sum up, this application has good elasticity, resistant high low temperature and curing rate through the waterproof glue film that obtains, still has excellent water-proof effects simultaneously. When the shielding case is welded by the SMT process on the upper plate normally, the temperature of the reflow oven enables the waterproof adhesive in the shielding case to be liquid, the silver waterproof adhesive layer has a little viscosity and can be wrapped on the inner chip of the shielding case, so that the chip is sealed, and the waterproofness of the shielding case to components is improved.
Preferably, the preparation method of the acrylic emulsion comprises the following steps:
mixing and stirring water, sodium dodecyl benzene sulfonate, an emulsifier and sodium bicarbonate to form a mixed solution;
heating to 80-85 ℃, adding part of methyl methacrylate, butyl acrylate, methacrylic acid and hydroxypropyl methacrylate into the mixed solution for reaction to obtain emulsion;
adding the rest methyl methacrylate into the emulsion, adding sodium bisulfite at the later stage of the reaction, preserving the heat for 30min, heating to 95-100 ℃, continuing preserving the heat for 50min, cooling to 50-55 ℃, and filtering to obtain the acrylic emulsion.
By adopting the technical scheme, the acrylic emulsion is prepared by adopting an emulsion semi-continuous polymerization process, wherein methyl methacrylate and butyl acrylate are selected as main monomers for preparation, and the methyl methacrylate is a hard monomer and has high Tg, hardness and strength. Meanwhile, methyl methacrylate is used as a functional monomer, is a hydrophilic monomer, can inhibit the generation of gel, improves the polymerization process and improves the adhesive force of the emulsion. Butyl acrylate is a soft monomer, has low Tg, and has good silencing properties and cohesiveness. The prepared acrylic emulsion has good hardness and viscosity by matching the methyl methacrylate and the butyl acrylate.
Preferably, the preparation of the acrylic emulsion is carried out in a reaction vessel with a stirring rate of 150 to 220r/min.
By adopting the technical scheme, the particle size of the latex particles is increased along with the increase of the stirring speed, and the gel rate is firstly reduced along with the increase of the stirring speed and then increased along with the increase of the stirring speed. This is because, when the acrylic emulsion is polymerized, but the stirring rate is increased, the monomer is dispersed into smaller monomer beads, resulting in a decrease in the number of micelles per unit volume, a decrease in the number of generated latex particles, and an increase in the solid latex particles; when the rotating speed is low, the unit dispersion degree is poor, partial monomer is generated, and even the phenomenon of layering is generated, so that the generation of gel is caused. Along with the increase of the stirring speed, the shearing action in the material is increased, and when the rotating speed is overlarge, the charge removed from the surface of the latex and the hydration layer are reduced, so that the latex is agglomerated to generate a gel phenomenon. In conclusion, the acrylic emulsion is prepared more favorably by controlling the stirring speed to be 150-220r/min.
Preferably, the shielding case body is bonded with the waterproof glue layer through bonding glue; the adhesive glue is one of organic silicon glue, phenolic resin glue, urea-formaldehyde resin glue, temperature-resistant epoxy glue and polyimide glue.
Through adopting above-mentioned technical scheme, the bonding glue can further improve the fastness of being connected between waterproof glue and the shield cover to the life of the shield cover that can take waterproof function is prolonged. The organic silicon glue, the phenolic resin glue, the urea-formaldehyde resin glue, the temperature-resistant epoxy glue and the polyimide glue have the excellent characteristics of high temperature resistance (below 400 ℃) and aging resistance, high adhesive force and good adhesive force.
Preferably, the waterproof glue layer further comprises 5-10 parts by weight of an auxiliary agent, the auxiliary agent is a mixture of acrylonitrile and triethanolamine, and the mass ratio of the acrylonitrile to the triethanolamine is 1: (1-5).
By adopting the technical scheme, under the combined action of acrylonitrile and triethanolamine, the decomposition of the high molecular polymer in the waterproof adhesive layer can be prevented, the two are mutually influenced and act synergistically, and the stability of the waterproof adhesive layer is obviously improved.
Preferably, the preparation method of the waterproof glue layer comprises the following steps:
s1, mixing sodium methyl silanol and acrylate and melting at a first temperature to form a first mixture;
s2, mixing the SIS and the SBS, heating and melting to a second temperature to form a second mixture;
s3, mixing the first mixture and the second mixture, adding the rest raw materials, and melting at a third temperature to form sol;
s4, extruding the sol to form a thin-layer high polymer material;
and S5, rolling the thin-layer high polymer material to form a waterproof adhesive layer.
By adopting the technical scheme, the preparation method of the waterproof adhesive layer is simple, and the prepared waterproof adhesive layer not only has good mechanical property, high resilience and tensile strength, but also has excellent waterproof effect.
Preferably, the first temperature is 40-50 ℃, the second temperature is 155-170 ℃, and the third temperature is 50-60 ℃.
By adopting the technical scheme, the temperature of the materials in the waterproof adhesive layer during mixing is optimized, and the waterproof adhesive layer can be prepared better.
Preferably, the waterproof glue layer is in a liquid state at 100-250 ℃.
By adopting the technical scheme, when the shielding case is normally welded by an SMT (surface mounting technology) process, the temperature of the reflow oven reaches 100-250 ℃, the waterproof adhesive layer in the shielding case is in a liquid state, and the waterproof adhesive layer has slight viscosity and can be wrapped on the inner core sheet of the shielding case, so that the chip is sealed, and the waterproof effect is achieved.
Preferably, the S/I of the SIS is (10-20): (80-90) and the viscosity of the SIS is 1500-2000Mpa · s.
By adopting the technical scheme, the larger the S/I (block ratio) of the SIS is, the lower the initial viscosity of the waterproof adhesive layer is, the higher the sustained viscosity is, the lower the melt viscosity is and the higher the softening point is, so that the waterproof adhesive layer has a good bonding and sealing effect on the chip when being heated to be changed into a solid state by controlling the block ratio of the SIS, and a certain waterproof effect is achieved. The larger the viscosity of the SIS is, the larger the molecular weight of the SIS is, the larger the tensile strength of the formed waterproof glue layer is, but the larger the viscosity is, the required amount of SBS which is matched with the SIS is also increased, so that the viscosity of the SIS is limited in a proper range, the waterproof glue layer has good strength, and the proper amount of solvent in the waterproof glue layer saves resources.
Preferably, the SBS has an S/B of (20-30): (70-80), and the viscosity of SBS is 4500-6000Mpa · s.
By adopting the technical scheme, the S/B in the SBS is increased, and the tensile strength and the hardness of the SBS are increased while the viscosity of the SBS is smaller. Therefore, the viscosity of SBS is kept in the range of 4500-6000 Mpa.S by controlling the ratio of S/B, so that the obtained waterproof glue layer has good tensile strength and viscosity and good adhesive force on the surface of the base material.
In summary, the present application includes at least one of the following beneficial technical effects:
1. according to the waterproof adhesive layer, the waterproof adhesive layer prepared by taking the styrene block copolymer and the waterproof agent as raw materials has excellent cohesiveness and waterproof effect, the waterproof adhesive layer is bonded in the shielding case, and then the shielding case with the waterproof function is welded with the PCB, so that the waterproof adhesive layer is heated and molten to wrap the chip, the chip is sealed, and the waterproof effect of the shielding case on components is improved;
2. according to the waterproof shield cover, the waterproof adhesive layer is bonded in the shield cover through the bonding adhesive, so that the connection strength of the shield cover and the waterproof adhesive layer is improved, and the service life of the shield cover with the waterproof function is prolonged;
3. this application is through adding the auxiliary agent in waterproof glue layer, can prevent the decomposition of the high molecular polymer in the waterproof glue layer to improve waterproof glue layer's stability.
Drawings
FIG. 1 is a sectional view of a shield case with a waterproof function according to embodiment 1 of the present application
Description of reference numerals: 1. a shield case body; 2. bonding the adhesive layer; 3. a waterproof glue layer.
Detailed Description
The present application is described in further detail below with reference to the accompanying fig. 1, preparation examples and examples.
Preparation examples
The preparation example discloses a preparation method of acrylic emulsion, which comprises the following specific processes:
s10, adding 220g of deionized water, 2g of sodium dodecyl benzene sulfonate, 3g of OP-10 emulsifier and 1.2g of sodium bicarbonate into a reaction container, and stirring and mixing at a stirring speed of 150r/min to obtain a mixed solution;
s20, heating the reaction container to 80 ℃, and adding 80g of methyl methacrylate, 80g of butyl acrylate, 6g of methacrylic acid and 6g of hydroxypropyl methacrylate into the mixed solution to react for 20min to obtain emulsion; wherein the CAS of methyl methacrylate: 80-62-6; CAS of butyl acrylate: 141-32-2; methacrylic acid CAS:79-41-4; hydroxypropyl methacrylate CAS:27813-02-1.
S30, adding 40g of methyl methacrylate into the emulsion, adding 0.15g of sodium bisulfite into a reaction container at the later stage of the reaction, preserving heat for 30min, heating to 95 ℃, continuing to preserve heat for 50min, finally cooling to 50 ℃, and filtering to obtain the acrylic emulsion.
Preparation example 2
This preparation is substantially the same as preparation 1, except that: the preparation method has different parameters of each step and specifically comprises the following steps:
s10, adding 220g of deionized water, 2g of sodium dodecyl benzene sulfonate, 3g of OP-10 emulsifier and 1.2g of sodium bicarbonate into a reaction container, and stirring and mixing at a stirring speed of 220r/min to obtain a mixed solution;
s20, heating the reaction container to 85 ℃, and adding 80g of methyl methacrylate, 80g of butyl acrylate, 6g of methacrylic acid and 6g of hydroxypropyl methacrylate into the mixed solution to react for 20min to obtain emulsion;
s30, adding 40g of methyl methacrylate into the emulsion, adding 0.15g of sodium bisulfite into a reaction container at the later stage of the reaction, preserving heat for 30min, heating to 100 ℃, continuing to preserve heat for 50min, finally cooling to 55 ℃, adjusting the pH value to 6.5-7 by ammonia water, and filtering to obtain the acrylic emulsion.
Examples
Examples 1 to 7
As shown in table 1, the main difference between examples 1 to 7 is that the amount of each raw material in the waterproof glue layer 3 is different.
As shown in fig. 1, the shielding case with waterproof function includes a shielding case body 1 and a waterproof adhesive layer 3 adhered to the inner top of the shielding case body 1 by adhesive, and the adhesive forms an adhesive layer 2 between the shielding case body 1 and the waterproof adhesive layer 3.
The implementation principle of the embodiment is as follows: when the upper board of the shielding case with the waterproof function is welded by an SMT process, the temperature of a reflow oven reaches 100-250 ℃, the waterproof adhesive layer 3 in the shielding case body 1 begins to melt and become liquid, and the liquid can be wrapped on a chip in the shielding case body 1, so that the chip is sealed, and the waterproof effect is achieved.
The adhesive in this embodiment is temperature-resistant epoxy adhesive, and in other embodiments, the adhesive may be silicone adhesive, phenolic resin adhesive, urea-formaldehyde resin adhesive, temperature-resistant epoxy adhesive, or polyimide adhesive. Wherein, the waterproof glue layer 3 is prepared by 45Kg of SIS, 15Kg of SBS, 10Kg of sodium methyl silanol and 10Kg of acrylic emulsion, wherein the acrylic emulsion is obtained by adopting the preparation example. Wherein the viscosity of the temperature-resistant epoxy adhesive is 4000-380000cps, and is purchased from the Bao Mao New Material technology Co., ltd, dongguan city; the S/I of the SIS is (10-20): (80-90), and the viscosity of the SIS is 1500-2000Mpa · s; the S/B of SBS is (20-30): (70-80), and the viscosity of SBS is 4500-6000Mpa · s; sodium methylsilanolate CAS:16589-43-8.
The implementation also discloses a preparation method of the waterproof glue layer 3, which specifically comprises the following steps:
s1, adding weighed sodium methyl silanol and acrylic ester into a reaction vessel according to a formula, mixing, and heating the temperature of the reaction vessel to 40 ℃ to form a first mixture;
s2, mixing the weighed SIS and SBS in another reaction vessel according to the formula, heating the temperature of the reaction vessel to 155 ℃, and forming a second mixture after the SIS and SBS are melted and uniformly mixed;
s3, adding the second mixture into the first mixture, heating the reaction container to 50 ℃, and mixing and melting to form sol;
s4, adding the sol into a double-screw extruder to extrude to form a thin-layer high polymer material; wherein the temperature of the front section of the extruder is 110-150 ℃, the temperature of the middle section is 160-210 ℃, the temperature of the rear section is 210-300 ℃, the current of a main engine is 40A, the melt pressure is 4Mpa, the rotating speed of the main engine is 200r/min, and the feeding rotating speed is 250r/min;
and S5, introducing the thin-layer high polymer material between a first roller and a second roller of rolling equipment for rolling to form the waterproof adhesive layer 3.
Table 1 examples 1-11 proportions of raw materials in the waterproof adhesive layer 3
Examples 8 to 11
Examples 8 to 11 are different from the preparation method of the waterproof adhesive layer 3 of example 1 except that the raw material ratio of the waterproof adhesive layer 3 in example 1 is different, specifically: and S3, adding the second mixture into the first mixture, weighing acrylonitrile and triethanolamine according to the formula, adding the acrylonitrile and the triethanolamine into a reaction vessel, heating the reaction vessel to 50 ℃, and mixing and melting to form sol.
Example 12
This example is substantially the same as example 1, except that: the acrylic emulsion was obtained in preparation example 2.
Example 13
This embodiment is substantially the same as the embodiment except that: the preparation method of the waterproof glue layer 3 is different, and specifically comprises the following steps: s1, adding weighed sodium methyl silanol and acrylic ester into a reaction vessel according to a formula, mixing, and heating the reaction vessel to 50 ℃ to form a first mixture; s2, mixing the weighed SIS and SBS in another reaction vessel according to the formula, heating the temperature of the reaction vessel to 170 ℃, and forming a second mixture after the SIS and SBS are melted and uniformly mixed; and S3, adding the second mixture into the first mixture, heating the reaction container to 60 ℃, and mixing and melting to form sol.
Comparative example
Comparative example 1
Different from the embodiment 1, a commercially available waterproof adhesive is adjusted to have an extrusion rate of 150 +/-25 mg/20s and a dispensing speed of 40mm/s, a waterproof adhesive layer is formed on the surface of a component, and then the waterproof adhesive layer is welded with a shielding case. Commercially available water-resistant adhesives are available from darzech new materials (huizhou city) ltd.
Comparative example 2
Unlike example 1, the amount of the styrenic block copolymer added in the waterproofing glue layer 3 was 50Kg (SIS: SBS = 1), i.e., the amount of each of SIS and SBS added was 25Kg.
Comparative example 3
Unlike example 1, the amount of the styrene block copolymer added to the waterproofing glue layer 3 was 80Kg (SIS: SBS =7 1), that is, the amount of SIS added was 70kg and the amount of SBS added was 10Kg.
Comparative example 4
Unlike example 1, the amount of the water repellent in the water repellent layer 3 was 10Kg (sodium methyl siliconate: acrylic emulsion =0: 1), that is, the amount of the acrylic emulsion was 10Kg.
Comparative example 5
Unlike example 1, the amount of the water repellent added to the water repellent layer 3 was 50Kg (sodium methylsilanolate: acrylic emulsion =4: 1), that is, the amount of the sodium methylsilanolate was 40Kg and the amount of the acrylic emulsion was 10Kg.
Performance detection
The assembly formed by the shielding cases and the components formed in the embodiments 1 to 13 and the comparative examples 1 to 5 is tested for glass strength p1 according to JC/T863-2011 and peel strength p2 after soaking for 24 hours at 25 ℃, and peel strength retention rate is obtained according to p2/p1 multiplied by 100 percent, so that the waterproof performance of the shielding case with the waterproof function is characterized, and the test results are recorded in a table 2 and analyzed.
TABLE 2 tables of data on the performance tests of examples 1 to 13 and comparative examples 1 to 5
The present application is described in detail below with reference to the test data provided in table 2.
Referring to table 2, it can be seen from example 1 and comparative example 1 that the waterproof glue layer 3 is prepared by preparing the waterproof raw material into the waterproof sol, and is fixed in the shield case body 1 by the adhesive, so as to obtain the shield case with the waterproof function, and the shield case is welded with the component (example 1). In the welding process, as the temperature of the reflow oven reaches the melting temperature of the waterproof glue layer 3, the waterproof glue becomes liquid, and the waterproof glue is wrapped on the chip in the shielding case, so that the chip is sealed, and a good waterproof effect is achieved. The waterproof glue is directly dispensed on the surface of the component to form a waterproof glue layer 3, and then the waterproof glue layer 3 is welded with the shielding case body 1 (comparative example 1), so that the waterproof glue layer 3 is damaged in the welding process, and the waterproofness of the component is reduced.
Referring to table 2, it can be seen from examples 1 to 4 and comparative examples 2 to 3 that the compounding of SIS and SBS can mutually compensate the respective disadvantages and play a complementary role, so that the obtained waterproof adhesive layer 3 has good elasticity, high and low temperature resistance and faster curing rate. Furthermore, the waterproof glue layer 3 can be rapidly solidified after being melted by reflow soldering at high temperature when in use, and good sealing performance is achieved. Therefore, the obtained waterproof glue layer 3 has good waterproof effect on components and parts within a proper addition amount and a proper mass ratio range of SIS and SBS.
Referring to table 2, it can be seen from examples 2, 5 to 6 and comparative examples 4 to 5 that increasing the content of the water repellent and changing the mass ratio of sodium methylsiliconate to acrylic emulsion in the water repellent within appropriate ranges gives a water repellent layer 3 having excellent water repellency to all components. The sodium methyl silanol can perform condensation reaction with air on components, and the synthesized high molecular compound is a reticular organic silicon resin film which has hydrophobicity, but can only exist in strong alkali; the acrylic emulsion has excellent waterproof performance, but can be decomposed in a strong alkaline environment, so that the waterproof effect is reduced. The sodium methylsiliconate is combined with the acrylic emulsion, but the acrylic emulsion is not destroyed by the strongly alkaline sodium methylsiliconate, and the waterproofness of the acrylic emulsion and the water-proof glue layer is improved.
Referring to table 2, it can be seen from examples 7 to 11 that the waterproof adhesive layer 3 obtained by changing the addition amount of the auxiliary agent and adjusting the mass ratio of acrylonitrile to triethanolamine in the auxiliary agent within a suitable range has better waterproof property for the components. The reason is that the auxiliary agent can prevent the high molecular polymer in the waterproof glue layer 3 from decomposing, so that the stability of the waterproof glue layer 3 is improved, and the waterproof effect of the waterproof glue layer 3 on components is further improved.
The specific embodiments and product examples are only for explaining the present application and are not limiting, and those skilled in the art can make modifications to the embodiments and product examples as required without any inventive contribution after reading the present specification, but all are protected by patent laws within the scope of the claims of the present application.
Claims (10)
1. The utility model provides a can take shield cover of waterproof function which characterized in that: comprises a shield cover body (1) and a waterproof glue layer (3) arranged in the shield cover body (1); the waterproof glue layer (3) is prepared from the following raw materials in parts by weight: 60-70 parts of styrene block copolymer and 20-30 parts of waterproof agent; the styrene block copolymer is a mixture of SIS and SBS, and the mass ratio of SIS to SBS is (3-5): 1; the waterproof agent is a mixture of sodium methyl silanol and acrylic emulsion, and the mass ratio of the sodium methyl silanol to the acrylic emulsion is (1-3): 1.
2. the shielding case with waterproof function according to claim 1, wherein: the preparation method of the acrylic emulsion comprises the following steps:
mixing and stirring water, sodium dodecyl benzene sulfonate, an emulsifier and sodium bicarbonate to form a mixed solution;
heating to 80-85 ℃, adding part of methyl methacrylate, butyl acrylate, methacrylic acid and hydroxypropyl methacrylate into the mixed solution for reaction to obtain emulsion;
adding the rest methyl methacrylate into the emulsion, adding sodium bisulfite at the later stage of reaction, keeping the temperature for 30min, heating to 95-100 ℃, keeping the temperature for 50min, cooling to 50-55 ℃, and filtering to obtain the acrylic emulsion.
3. The shielding case with waterproof function according to claim 2, wherein: the preparation of the acrylic emulsion is carried out in a reaction vessel, and the stirring speed of the reaction vessel is 150-220r/min.
4. The shielding case with waterproof function according to claim 1, wherein: the shielding case body (1) is bonded with the waterproof glue layer (3) through bonding glue; the adhesive glue is one of organic silicon glue, phenolic resin glue, urea-formaldehyde resin glue, temperature-resistant epoxy glue and polyimide glue.
5. The shielding case with waterproof function according to claim 1, wherein: the waterproof adhesive layer (3) further comprises 5-10 parts by weight of an auxiliary agent, wherein the auxiliary agent is a mixture of acrylonitrile and triethanolamine, and the mass ratio of the acrylonitrile to the triethanolamine is 1: (1-5).
6. The shielding case with waterproof function according to claim 5, wherein: the preparation method of the waterproof glue layer (3) comprises the following steps:
s1, mixing sodium methyl silanol and acrylate and melting at a first temperature to form a first mixture;
s2, mixing the SIS and the SBS, heating and melting to a second temperature to form a second mixture;
s3, mixing the first mixture and the second mixture, adding the rest raw materials, and melting at a third temperature to form sol;
s4, extruding the sol to form a thin-layer high polymer material;
s5, the thin-layer high polymer material is subjected to rolling to form a waterproof glue layer (3).
7. The shield cover with waterproof function according to claim 6, wherein: the first temperature is 40-50 ℃, the second temperature is 155-170 ℃, and the third temperature is 50-60 ℃.
8. The shielding case with waterproof function according to claim 6, wherein: the waterproof glue layer (3) is in a liquid state at the temperature of 100-250 ℃.
9. The shield cover with waterproof function according to claim 6, wherein: the S/I of the SIS is (10-20): (80-90) and the viscosity of the SIS is 1500-2000Mpa · s.
10. The shielding case with waterproof function according to claim 6, wherein: the S/B of SBS is (20-30): (70-80), and the viscosity of SBS is 4500-6000Mpa · s.
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| CN202210849877.2A CN115418186A (en) | 2022-07-20 | 2022-07-20 | Shielding case with waterproof function |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015060224A1 (en) * | 2013-10-25 | 2015-04-30 | 株式会社クラレ | Hot melt adhesive composition |
| CN106366239A (en) * | 2016-09-30 | 2017-02-01 | 哈尔滨市五星防水材料有限公司 | Macromolecular polymer water-proofing agent and preparation method and usage method thereof |
| CN112521784A (en) * | 2020-12-07 | 2021-03-19 | 潍坊昌大建设集团有限公司 | Concrete surface waterproof agent and construction method based on same |
| CN213991562U (en) * | 2020-12-31 | 2021-08-17 | 深圳创维数字技术有限公司 | Protective adhesive shielding case, double shielding case and circuit board |
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2022
- 2022-07-20 CN CN202210849877.2A patent/CN115418186A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015060224A1 (en) * | 2013-10-25 | 2015-04-30 | 株式会社クラレ | Hot melt adhesive composition |
| CN106366239A (en) * | 2016-09-30 | 2017-02-01 | 哈尔滨市五星防水材料有限公司 | Macromolecular polymer water-proofing agent and preparation method and usage method thereof |
| CN112521784A (en) * | 2020-12-07 | 2021-03-19 | 潍坊昌大建设集团有限公司 | Concrete surface waterproof agent and construction method based on same |
| CN213991562U (en) * | 2020-12-31 | 2021-08-17 | 深圳创维数字技术有限公司 | Protective adhesive shielding case, double shielding case and circuit board |
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