Solvent-free peroxidation curing organic silicon molded plastic as well as preparation method and application thereof

Abstract

The invention provides a solvent-free peroxidation-cured organic silicon molded plastic and a preparation method and application thereof, and the solvent-free peroxidation-cured organic silicon molded plastic comprises the following preparation raw materials by weight: 110-130 parts of solvent-free organic silicon resin; 20 to 350 parts of filler; 0.5-3 parts of a release agent; 0.5 to 5 parts of a peroxide initiator; 0.1-3 parts of a coloring agent; the solvent-free organic silicon resin has a structure as shown in a formula (I). The preparation raw materials of the organosilicone molded plastic provided by the invention take the cage-shaped organosilicone resin as a main component, the filler is filled, and the peroxide initiator is added, so that the organosilicone molded plastic can be stored for a long time at room temperature and can be rapidly cured at high temperature; the cured molded plastic has the characteristics of low shrinkage rate, excellent impact strength, higher bending strength, higher dielectric strength, higher volume resistivity, lower water absorption rate, excellent flame retardant property and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of silicone resins and relates to a solvent-free peroxide-cured organic silicon molded plastic and a preparation method and application thereof. Background Art

[0002] Silicone molding compound has good transfer molding fluidity, fast curing speed, small shrinkage after molding, and good dimensional stability. The cured silicone molding compound products have good high and low temperature resistance, and can be used for a long time in the range of -60 to +250℃, and the short-term heat resistance can reach 350℃. Its mechanical properties are slightly reduced at high temperatures. In addition, it also has excellent arc and corona resistance, chemical resistance, hydrophobic moisture resistance, ozone resistance, weather aging resistance and other properties. Its dielectric properties are very excellent and change very little in a wide temperature and frequency range.

[0003] Silicone molding compounds are mainly used to package electronic components, semiconductor tubes, integrated circuits, etc. Using the above-mentioned molding compounds to replace metal, glass, and ceramic packaging not only simplifies the process and reduces labor intensity, but also increases the product qualification rate to about 99%, reducing the cost of product packaging. Silicone molding compounds with different formulations are used in different occasions.

[0004] Silicone molded plastics used for encapsulating electronic components, semiconductor transistors, integrated circuits, etc. have the characteristics of heat resistance, non-flammability, low water absorption, good moisture resistance and non-corrosion. They can still maintain stable electrical insulation and mechanical properties over a wide range of temperature, humidity and frequency, thereby protecting the encapsulated semiconductor components from moisture, dust, impact, vibration and temperature.

[0005] However, the current organosilicon molding materials contain solvents and are cured by a condensation reaction system. Water vapor is easily generated during the curing process, and there are disadvantages such as high curing temperature and long curing time.

[0006] Therefore, it is expected in the art to develop a solvent-free silicone molding compound, which has a lower curing temperature and a shorter curing time than solvent-containing silicone molding compounds, thus saving energy and time and being environmentally friendly. Summary of the invention

[0007] In view of the deficiencies in the prior art, the object of the present invention is to provide a solvent-free peroxide-cured silicone molded plastic and a preparation method and application thereof.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a solvent-free peroxide-cured silicone molded plastic. The raw materials for preparing the solvent-free peroxide-cured silicone molded plastic include the following components in parts by weight:

[0010]

[0011] The solvent-free silicone resin has a structure shown in the following formula (I):

[0012] [RSiO 3 / 2 ] a [PhSiO 3 / 2 ] b [RRSiO 2 / 2 ] c [R 1 RRSiO 1 / 2 ] d Formula (I);

[0013] wherein R is independently selected from an organic group that does not contain aliphatic carbon-carbon multiple bonds;

[0014] R 1 is selected from monovalent unsubstituted or substituted SiC-bonded hydrocarbon groups having aliphatic carbon-carbon multiple bonds;

[0015] Ph is phenyl;

[0016] a, b, c, and d represent molar ratios and satisfy the following conditions: a is 0.1 to 0.7 (e.g., 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, etc.), b is 0.05 to 0.5 (e.g., 0.05, 0.06, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, etc.), c is 0.1 to 0.5 (e.g., 0.1, 0.2, 0.3, 0.4, 0.5, etc.), d is 0.05 to 0.6 (e.g., 0.05, 0.06, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, etc.), and a+b+c=1.

[0017] The raw materials for preparing the organic silicon molded plastic provided by the present invention are mainly composed of caged organic silicon resin, filled with fillers, and added with peroxide initiators. The molded plastic can be stored for a long time at room temperature and can be quickly cured at high temperatures. The cured molded plastic has low heat shrinkage, low water absorption, flame retardancy, high temperature resistance, moisture resistance, high mechanical strength, and electrical insulation performance that changes very little with temperature.

[0018] In the present invention, the raw materials for preparing the solvent-free peroxide-cured silicone molded plastic are calculated by weight, and the amount of the solvent-free silicone resin can be 110 parts, 112 parts, 114 parts, 116 parts, 118 parts, 120 parts, 122 parts, 124 parts, 126 parts, 128 parts, 130 parts, etc.

[0019] In the present invention, the raw materials for preparing the solvent-free peroxide-cured silicone molded plastic are measured by weight, and the amount of filler used can be 20 parts, 40 parts, 60 parts, 80 parts, 100 parts, 120 parts, 140 parts, 160 parts, 180 parts, 200 parts, 220 parts, 240 parts, 260 parts, 280 parts, 300 parts, 320 parts, 340 parts, 350 parts, etc.

[0020] In the present invention, the raw materials for preparing the solvent-free peroxide-cured silicone molded plastic are measured in parts by weight, and the amount of the release agent used can be 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, etc.

[0021] In the present invention, the raw materials for preparing the solvent-free peroxide-cured silicone molded plastic are measured in parts by weight, and the amount of peroxide initiator used can be 0.5 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, etc.

[0022] In the present invention, the raw materials for preparing the solvent-free peroxide-cured silicone molded plastic are measured in parts by weight, and the amount of the colorant used can be 0.1 parts, 0.2 parts, 0.3 parts, 0.5 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, etc.

[0023] Preferably, the R is independently selected from halogen, -CN, -SCN, -NCO or a substituted or unsubstituted saturated hydrocarbon group of C1 to C6 (e.g., C1, C2, C3, C4, C5, C6); the substituted substituent is selected from a straight chain or branched alkyl group of C1 to C6 (e.g., C1, C2, C3, C4, C5, C6).

[0024] Preferably, the R is independently selected from any one of methyl, dimethyl, ethyl and propyl.

[0025] Preferably, the R 1 Selected from vinyl.

[0026] Preferably, the solvent-free silicone resin is solid at 25°C, and has a melting point lower than 45°C, such as 44°C, 40°C, 38°C, 35°C, etc.

[0027] Preferably, the solvent-free silicone resin is prepared by the following method:

[0028] (A) mixing methyltrialkoxysilane, phenyltrialkoxysilane, dimethyldialkoxysilane, vinyl single end cap and water, adding an acid catalyst, hydrolyzing, adding a pH adjuster, standing to separate layers, removing the water layer, and obtaining a hydrolyzed silanol solution;

[0029] (B) adding a concentrator to the hydrolyzed silanol solution obtained in step (A) to carry out a concentration reaction, wherein the material in the kettle becomes a colorless, transparent, homogeneous system, and then removing alcohol (such as methanol, ethanol, low molecular weight silanol, etc.) and water under vacuum conditions until dripping is not obvious, thereby obtaining the solvent-free silicone resin.

[0030] The solvent-free organic silicon resin provided by the invention has no solvent added in the preparation process, vinyl end-capping is introduced into the organic silicon resin, and the caged silicon resin is synthesized by a special reflux concentration formula process.

[0031] Preferably, the methyltrialkoxysilane includes methyltrimethoxysilane and / or methyltriethoxysilane, preferably methyltriethoxysilane.

[0032] Preferably, the phenyltrialkoxysilane comprises phenyltrimethoxysilane and / or phenyltriethoxysilane, preferably phenyltriethoxysilane.

[0033] Preferably, the dimethyldialkoxysilane includes dimethyldiethoxysilane and / or dimethyldimethoxysilane, preferably dimethyldiethoxysilane.

[0034] Preferably, the molar ratio of methyltrialkoxysilane to phenyltrialkoxysilane is (0.1-0.7):(0.05-0.5), 0.1-0.7 can be, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, etc., and 0.05-0.5 can be, for example, 0.05, 0.06, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, etc.

[0035] Preferably, the molar ratio of methyltrialkoxysilane to dimethyldialkoxysilane is (0.1-0.7):(0.1-0.5), 0.1-0.7 can be, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, etc., and 0.1-0.5 can be, for example, 0.1, 0.2, 0.3, 0.4, 0.5, etc.

[0036] Preferably, the molar ratio of the methyltrialkoxysilane to the vinyl single head is (0.1-0.7):(0.05-0.6), 0.1-0.7 can be, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, etc., and 0.05-0.6 can be, for example, 0.05, 0.06, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, etc.

[0037] In the present invention, the feeding amounts of methyltrialkoxysilane, phenyltrialkoxysilane, dimethyldialkoxysilane and vinyl single-end meet the following conditions: a is 0.1-0.7, b is 0.05-0.5, c is 0.1-0.5, d is 0.05-0.6, and a+b+c=1.

[0038] Preferably, the ratio of the molar number of water in step (A) to the total molar number of alkoxy groups in alkoxysilane (i.e., methyltrialkoxysilane, phenyltrialkoxysilane, dimethyldialkoxysilane, and vinyl single-capped silane) is (0.5-1.1):1, for example, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, etc.

[0039] Preferably, the acid catalyst in step (A) comprises any one or a combination of at least two of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, boric acid, formic acid, acetic acid, propionic acid, oxalic acid, maleic acid, methanesulfonic acid, camphor, sulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, trifluoropropionic acid, trifluoromethanesulfonic acid, acid clay, and sulfonated ion exchange resin, preferably hydrochloric acid and / or formic acid.

[0040] Preferably, the amount of the acid catalyst in step (A) is such that the pH of the system is 3 to 4.5, for example, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, etc.

[0041] Preferably, the hydrolysis temperature in step (A) is 30°C to 75°C, for example, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 75°C, etc., and the hydrolysis time is 1h to 2h, for example, 1h, 1.5h, 2h, etc.

[0042] Preferably, the pH adjuster in step (A) comprises silazane and / or alkaline substances.

[0043] Preferably, the silazane comprises hexamethyldisilazane.

[0044] Preferably, the amount of the pH adjuster added in step (A) is such that the pH of the system is 5 to 8, for example, 5, 5.5, 6, 6.5, 7, 7.5, 8, etc.

[0045] Preferably, the concentrator in step (B) comprises any one of zinc octoate, triethanolamine, zinc isooctanoate, zinc naphthenate, cobalt naphthenate, potassium hydroxide, or a combination of at least two thereof, preferably zinc octoate.

[0046] Preferably, the added amount of the concentrator is 100 to 2000 ppm of alkoxysilane (i.e., methyltrialkoxysilane, phenyltrialkoxysilane, dimethyldialkoxysilane, and vinyl single head as a whole), for example, 100 ppm, 200 ppm, 300 ppm, 500 ppm, 800 ppm, 1000 ppm, 1200 ppm, 1400 ppm, 1600 ppm, 1800 ppm, 2000 ppm, etc.

[0047] Preferably, the adding of the concentrator in step (B) is specifically: adding the concentrator under the condition of reflux stirring and hydrolyzing the silanol solution at 75°C to 150°C (for example, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, etc.).

[0048] Preferably, the concentration reaction time in step (B) is 2 h to 8 h, for example, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, etc.

[0049] Preferably, the vacuum condition in step (B) is -0.08 MPa to -0.09 MPa, such as -0.08 MPa, -0.085 MPa, -0.09 MPa, etc.

[0050] Preferably, the temperature for removing low molecular weight substances and water in step (B) is 100°C to 170°C, for example, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, etc., and the time for removing low molecular weight substances and water is 1h to 2h, for example, 1h, 1.5h, 2h, etc.

[0051] Preferably, the filler comprises nano-inorganic matter and fiber.

[0052] Preferably, the nano inorganic material includes quartz powder (200-8000 mesh), talc powder (325-5000 mesh), mica powder (20-2500 mesh), gypsum or white carbon black (average particle size 11nm-100nm, specific surface area 45m 2 ·g -1 ~400m 2 ·g -1 ) or a combination of at least two of them.

[0053] Preferably, the fibers include any one of glass fiber (1 mm to 25 mm), glass cloth (thickness 0.28 μm to 0.173 mm) or asbestos (fiber length 3 mm to 50 mm) or a combination of at least two thereof.

[0054] Preferably, the release agent includes any one of calcium stearate, zinc stearate or calcium oleate, or a combination of at least two thereof.

[0055] Preferably, the peroxide initiator includes any one of dibenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butyl perbenzoate, di-tert-butyl peroxide, diisopropylbenzene peroxide, and 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane, or a combination of at least two thereof.

[0056] Preferably, the dye comprises carbon black, ultramarine (Na 6 A1 4 Si 6 S 4 O 20 ), any one of yellow iron oxide, red iron oxide or titanium dioxide, or a combination of at least two thereof.

[0057] In a second aspect, the present invention provides a method for preparing the solvent-free peroxide-cured silicone molded plastic as described in the first aspect, the preparation method comprising the following steps:

[0058] (1) adding a formulated amount of solvent-free silicone resin and part of the filler to a kneader for kneading, removing low molecular weight and water, adding the remaining filler and a release agent, kneading them uniformly, and then mixing them uniformly on a double-roll mill, and then adding a peroxide initiator and a dye, and rolling them after thinning them uniformly to obtain a sheet;

[0059] (2) The sheet is molded and cured to obtain the solvent-free peroxide silicone molded plastic.

[0060] The invention discloses a heat-curing organic silicon molded plastic which is a body-shaped structure formed by mixing various functional materials and then using high-temperature molding free radicals to initiate cross-linking in the presence of a peroxide initiator.

[0061] Preferably, the part of filler in step (1) accounts for 96% to 99.5% of the total weight of the filler, for example, 96%, 97%, 98%, 99%, 99.5%, etc.

[0062] Preferably, the molding in step (2) is carried out at 70°C to 170°C (for example, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, etc.) and 5 to 30 MPa (for example, 5 MPa, 10 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, etc.).

[0063] Preferably, the molding time in step (2) is 5 min to 30 min, for example, 5 min, 8 min, 10 min, 12 min, 14 min, 16 min, 18 min, 20 min, 22 min, 24 min, 26 min, 28 min, 30 min, etc.

[0064] The organic silicon molded plastic provided by the present invention has silicone resin with a cage-type molecular structure as a main component, has a silicon-oxygen polymer skeleton, and also has organic side chains such as methyl and phenyl. It is reinforced by adding nano-inorganic substances and fiber composite functional fillers. In this way, the organic silicon material structure has both organic groups and inorganic structures. Under high temperature, the molded vinyl is cross-linked by free radicals to form a network. Therefore, the organic silicon molded plastic is a special polymer material with a semi-organic and semi-inorganic structure, has unique excellent properties, and has very wide application value.

[0065] In a third aspect, the present invention provides a use of the solvent-free peroxide-cured silicone molded plastic as described in the first aspect in packaging electronic components, semiconductor products, and integrated circuits.

[0066] Compared with the prior art, the present invention has at least the following beneficial effects:

[0067] The raw materials for preparing the organic silicon molded plastic provided by the present invention are mainly composed of caged organic silicon resin, filled with fillers, and added with peroxide initiators. The organic silicon molded plastic can be stored for a long time at room temperature and can be quickly cured at high temperatures. The cured molded plastic has the characteristics of low shrinkage, excellent impact strength and high bending strength, high dielectric strength and high volume resistivity, low water absorption, excellent flame retardant properties, and the like. DETAILED DESCRIPTION

[0068] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0069] Example 1

[0070] In this embodiment, a solvent-free peroxide-cured silicone molded plastic is provided, and the preparation method comprises the following steps:

[0071] (1) Dimethyldiethoxysilane: 614 g, methyltriethoxysilane: 800 g, phenyltriethoxysilane: 914 g, vinyl single end cap: 300 g, H 2O: 637g, add it into the enamel reaction kettle by weight and mix it, then add hydrochloric acid: 0.25g dropwise, then start the stirrer for hydrolysis, heat to 70℃ for hydrolysis for 2h, add hexamethyldisilazane: 1.5g, adjust the pH of the system to 7, let it stand for stratification, drain ethanol and brine, wash the oil layer with distilled water three times, drain the water, and obtain a hydrolyzed silanol solution;

[0072] (2) adding 1.7 g of zinc octoate to the hydrolyzed silanol solution obtained in step (1), refluxing and stirring at 120° C. for 4 h to polycondense to obtain a concentrated silicone resin, and then heating to 150° C. and dehydrating under vacuum at -0.09 MPa for 2 h until the droplet of liquid is 2 drops / s and no longer obvious, to obtain a solvent-free silicone resin;

[0073] (3) 1200 g of the solvent-free silicone resin obtained in step (2) with a specific surface area of ​​300 m 2 ·g -1 ) White carbon black: 600g, length (10mm) glass fiber: 1200g, quartz powder (6000 mesh): 1400g are added to a kneader and kneaded uniformly, and then low molecular weight and water are removed by vacuum, and then gypsum: 20g, calcium stearate: 22g are added, and after kneading uniformly, the mixture is rolled on a double-roll open mill, and then dibenzoyl peroxide: 12g, ultramarine: 24g are added, and after thinning and uniformity, the mixture is rolled to obtain a sheet;

[0074] (4) The sheet is molded at 110° C. and 15 MPa for 15 min and then cured to obtain the solvent-free peroxide-cured silicone molded plastic.

[0075] Example 2

[0076] In this embodiment, a solvent-free peroxide-cured silicone molded plastic is provided, and the preparation method comprises the following steps:

[0077] (1) Dimethyldimethoxysilane: 497g, methyltrimethoxysilane: 610g, phenyltrimethoxysilane: 752g, vinyl single head: 300g, H 2 O; 630g, add it into the enamel reaction kettle by weight and mix it, then add hydrochloric acid: 0.25g, then start the stirrer for hydrolysis, heat it to 70℃ for hydrolysis for 2h, add hexamethyldisilazane: 1.6g, adjust the pH of the system to 7, let it stand for stratification, drain methanol, ethanol and brine, wash the oil layer with distilled water three times, drain the water, and obtain a hydrolyzed silanol solution;

[0078] (2) adding 1.7 g of zinc octoate to the hydrolyzed silanol solution obtained in step (1), refluxing and stirring at 120° C. for 4 h to polycondense to obtain a concentrated silicone resin, and then heating to 150° C. and dehydrating under vacuum at -0.09 MPa for 2 h until the droplet of liquid is 2 drops / s and no longer obvious, to obtain a solvent-free silicone resin;

[0079] (3) 1200 g of the solvent-free silicone resin obtained in step (2) with a specific surface area of ​​300 m 2 ·g -1 ) 800g of white carbon black, 1400g of asbestos with a fiber length of 30mm, and 1000g of quartz powder with a particle size of 3000 mesh are added to a kneader and kneaded evenly, and then low molecular weight and water are removed by vacuum, and then 20g of gypsum and 24g of calcium stearate are added, and after kneading evenly, the mixture is rolled on a double-roll mill, and then 7g of 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane and 24g of ultramarine are added, and after thinning and uniformity, the mixture is rolled to obtain a sheet;

[0080] (4) The sheet is molded at 170° C. @ 20 MPa for 10 min and then cured to obtain the solvent-free peroxide-cured silicone molded plastic.

[0081] Example 3

[0082] In this embodiment, a solvent-free peroxide-cured silicone molded plastic is provided, and the preparation method comprises the following steps:

[0083] (1) Dimethyldiethoxysilane: 579 g, methyltriethoxysilane: 482 g, phenyltrimethoxysilane: 971 g, vinyl single end cap: 351 g, H 2 O; 590g, add it into the enamel reaction kettle by weight and mix it, then add hydrochloric acid: 0.23g, then start the stirrer for hydrolysis, heat it to 70℃ and hydrolyze for 2h, add hexamethyldisilazane: 1.6g, adjust the pH of the system to 7, drain methanol, ethanol and brine, wash the oil layer with distilled water three times, drain the water, and obtain a hydrolyzed silanol solution;

[0084] (2) adding 1.7 g of zinc octoate to the hydrolyzed silanol solution obtained in step (1), refluxing and stirring at 120° C. for 4 h to polycondense to obtain a concentrated silicone resin, and then heating to 150° C. and dehydrating under vacuum at -0.09 MPa for 2 h until the liquid dripping is 2 drops / s and no obvious droplets are produced, thereby obtaining a solvent-free silicone resin;

[0085] (3) 1200 g of the solvent-free silicone resin obtained in step (2) with a specific surface area of ​​300 m 2 ·g -1) 1000g of white carbon black, 1200g of asbestos (fiber length 30mm), and 800g of quartz powder (6000 mesh) are added to a kneader and kneaded uniformly, and then low molecular weight and water are removed by vacuum, and then 20g of gypsum and 25g of calcium stearate are added. After kneading uniformly, the mixture is rolled on a double-roll open mill, and then 7g of 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane and 15g of ultramarine are added. After thinning and uniformization, the mixture is rolled to obtain a sheet;

[0086] (4) The sheet is molded at 170° C. @ 10 MPa for 10 min and then cured to obtain the solvent-free peroxide-cured silicone molded plastic.

[0087] Example 4

[0088] In this embodiment, a solvent-free peroxide-cured silicone molded plastic is provided, and the preparation method comprises the following steps:

[0089] (1) Dimethyldimethoxysilane: 376g, methyltrimethoxysilane: 341g, phenyltrimethoxysilane: 1348g, vinyl single end cap: 243g, H 2 O; 583g, add it into the enamel reaction kettle by weight and mix it, then add hydrochloric acid: 0.21g, then start the stirrer for hydrolysis, heat it to 70℃ for hydrolysis for 2h, add hexamethyldisilazane: 1.5g, adjust the pH of the system to 7, drain methanol, ethanol, and brine, wash the oil layer with distilled water three times, drain the water, and obtain a hydrolyzed silanol solution;

[0090] (2) adding 1.3 g of zinc octoate to the hydrolyzed silanol solution obtained in step (1), refluxing and stirring at 120° C. for 4 h to polycondense to obtain a concentrated silicone resin, and then heating to 150° C. and dehydrating under vacuum at -0.09 MPa for 2 h until the liquid dripping is 2 drops / s and no longer obvious, to obtain a solvent-free silicone resin;

[0091] (3) 1200 g of the solvent-free silicone resin obtained in step (2) with a specific surface area of ​​300 m 2 ·g -1 ) White carbon black: 600g, fiber length (30mm) asbestos: 1600g, (6000 mesh) quartz powder: 1000g are added to a kneader and kneaded evenly, and then low molecular weight and water are removed by vacuum, and then gypsum: 20g, calcium stearate: 24g are added, and after kneading evenly, roll sheeting is performed on a double-roll open mill, and then 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane: 7g and ultramarine: 24g are added, and after thinning and uniformity, roll sheeting is performed to obtain a sheet;

[0092] (4) The sheet is molded at 170° C. @ 10 MPa for 10 min and then cured to obtain the solvent-free peroxide-cured silicone molded plastic.

[0093] Comparative Example 1

[0094] The only difference between this comparative example and Example 1 is that no vinyl single end cap is added in step (1).

[0095] The performance of the solvent-free peroxide-cured silicone molded plastics provided in the examples and comparative examples was tested, and the results are shown in Table 1.

[0096] Table 1

[0097]

[0098] It can be seen from Table 1 that the solvent-free peroxide-cured silicone molded plastics provided in the embodiments of the present invention have low shrinkage (0.01%), excellent impact strength (4.5-6.0 kJ / m 2 ), higher flexural strength (73-80 MPa), higher dielectric strength (greater than 14 Kv / mm), higher volume resistivity (greater than 1×10 14 Ω·cm), low water absorption (less than 0.1%) and excellent flame retardant properties (all V0).

[0099] Compared with Example 1, the shrinkage rate of the solvent-free peroxide-cured silicone molded plastic provided in Comparative Example 1 is significantly increased, and the impact strength, bending strength and compression strength are significantly reduced.

[0100] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the solvent-free peroxide-cured silicone molded plastic and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A solvent-free peroxide-cured silicone molded plastic, characterized in that: The raw materials for preparing the solvent-free peroxide-cured silicone molded plastic include the following components in parts by weight: The solvent-free silicone resin has a structure shown in the following formula (I): [RSiO 3 / 2 a [PhSiO 3 / 2 b [RRSiO 2 / 2 c [R 1 RRSiO 1 / 2 d Formula (I);​​​​ wherein R is independently selected from an organic group that does not contain aliphatic carbon-carbon multiple bonds; R 1 is selected from monovalent unsubstituted or substituted SiC-bonded hydrocarbon groups having aliphatic carbon-carbon multiple bonds; Ph is phenyl; a, b, c, and d represent molar ratios and satisfy the following conditions: a is 0.1 to 0.7, b is 0.05 to 0.5, c is 0.1 to 0.5, d is 0.05 to 0.6, and a+b+c=1.

2. The solvent-free peroxide-cured silicone molded plastic according to claim 1, characterized in that: The R's are each independently selected from halogen, -CN, -SCN, -NCO or a C1-C6 substituted or unsubstituted saturated hydrocarbon group; the substituted substituents are selected from C1-C6 straight-chain or branched alkyl groups; Preferably, each of the R groups is independently selected from any one of methyl, dimethyl, ethyl and propyl; Preferably, the R 1 Selected from vinyl.

3. The solvent-free peroxide-cured silicone molded plastic according to claim 1 or 2, characterized in that: The solvent-free silicone resin is solid at 25°C and has a melting point below 45°C.

4. The solvent-free peroxide-cured silicone molded plastic according to any one of claims 1 to 3, characterized in that: The solvent-free silicone resin is prepared by the following method: (A) mixing methyltrialkoxysilane, phenyltrialkoxysilane, dimethyldialkoxysilane, vinyl single end cap and water, adding an acid catalyst, hydrolyzing, adding a pH adjuster, standing to separate layers, removing the water layer, and obtaining a hydrolyzed silanol solution; (B) adding a concentrator to the hydrolyzed silanol solution obtained in step (A) to carry out a concentration reaction, and then removing alcohol and water under vacuum conditions to obtain the solvent-free organosilicon resin.

5. The solvent-free peroxide-cured silicone molded plastic according to claim 4, characterized in that: The methyltrialkoxysilane includes methyltrimethoxysilane and / or methyltriethoxysilane, preferably methyltriethoxysilane; Preferably, the phenyltrialkoxysilane comprises phenyltrimethoxysilane and / or phenyltriethoxysilane, preferably phenyltriethoxysilane; Preferably, the dimethyldialkoxysilane comprises dimethyldiethoxysilane and / or dimethyldimethoxysilane, preferably dimethyldiethoxysilane; Preferably, the molar ratio of the methyltrialkoxysilane to the phenyltrialkoxysilane is (0.1-0.7):(0.05-0.5); Preferably, the molar ratio of the methyltrialkoxysilane to the dimethyldialkoxysilane is (0.1-0.7):(0.1-0.5); Preferably, the molar ratio of the methyltrialkoxysilane to the vinyl monocapsule is (0.1-0.7):(0.05-0.6); Preferably, the ratio of the molar number of water in step (A) to the total molar number of alkoxy groups in the alkoxysilane is (0.5-1.1):1; Preferably, the acid catalyst in step (A) comprises any one or a combination of at least two of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, boric acid, formic acid, acetic acid, propionic acid, oxalic acid, maleic acid, methanesulfonic acid, camphor, sulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, trifluoropropionic acid, trifluoromethanesulfonic acid, acid clay, and sulfonated ion exchange resin, preferably hydrochloric acid and / or formic acid; Preferably, the amount of the acid catalyst used in step (A) is such that the pH of the system is 3 to 4.5; Preferably, the hydrolysis temperature in step (A) is 30°C to 75°C, and the hydrolysis time is 1h to 2h; Preferably, the pH adjuster in step (A) comprises silazane and / or alkaline substances; Preferably, the silazane comprises hexamethyldisilazane; Preferably, the amount of the pH adjuster added in step (A) is such that the pH of the system is 5-8.

6. The solvent-free peroxide-cured silicone molded plastic according to claim 4 or 5, characterized in that: The concentrator in step (B) comprises any one of zinc octoate, triethanolamine, zinc isooctanoate, zinc naphthenate, cobalt naphthenate, and potassium hydroxide, or a combination of at least two thereof, preferably zinc octoate; Preferably, the concentration of the concentrator is 100 to 2000 ppm of the alkoxysilane; Preferably, the adding of the concentrator in step (B) is specifically: adding the concentrator under the condition of reflux stirring and hydrolyzing the silanol solution at 75° C. to 150° C.; Preferably, the concentration reaction time in step (B) is 2h to 8h; Preferably, the vacuum condition in step (B) is -0.08 MPa to -0.09 MPa; Preferably, the temperature for removing low molecular weight substances and water in step (B) is 100° C. to 170° C., and the time for removing low molecular weight substances and water is 1 h to 2 h.

7. The solvent-free peroxide-cured silicone molded plastic according to any one of claims 1 to 6, characterized in that: The filler includes nano inorganic matter and fiber; Preferably, the nano inorganic material comprises any one of quartz powder, talcum powder, mica powder, gypsum or white carbon black, or a combination of at least two thereof; Preferably, the fiber comprises any one of glass fiber, glass cloth or asbestos, or a combination of at least two thereof; Preferably, the release agent comprises any one of calcium stearate, zinc stearate or calcium oleate or a combination of at least two thereof; Preferably, the peroxide initiator comprises any one of dibenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butyl perbenzoate, di-tert-butyl peroxide, diisopropylbenzene peroxide, and 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane, or a combination of at least two thereof; Preferably, the coloring agent includes any one of carbon black, ultramarine blue, yellow iron oxide, red iron oxide or titanium dioxide, or a combination of at least two thereof.

8. A method for preparing a solvent-free peroxide-cured silicone molded plastic as claimed in any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: (1) adding a formulated amount of solvent-free silicone resin and part of the filler to a kneader for kneading, removing low molecular weight and water, adding the remaining filler and a release agent, kneading them uniformly, and then mixing them uniformly on a double-roll mill, and then adding a peroxide initiator and a dye, and rolling them after thinning them uniformly to obtain a sheet; (2) The sheet is molded and cured to obtain the solvent-free peroxide silicone molded plastic.

9. The preparation method according to claim 8, characterized in that: The part of filler in step (1) accounts for 96% to 99.5% of the total weight of the filler; Preferably, the molding in step (2) is performed at 70°C to 170°C and 5 to 30 MPa; Preferably, the molding time in step (2) is 5 min to 30 min.

10. Use of the solvent-free peroxide-cured silicone molded plastic according to any one of claims 1 to 7 in packaging electronic components, semiconductor products, and integrated circuits.

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