1193results about How to "Excellent heat and humidity resistance" patented technology

A photocurable resin composition for sealing an organic EL device is provided, which can seal the organic EL device without exerting any bad influence on the device, thereby suppress the formation and growth of dark spots positively, and which can ensure a high transmittance of light, thereby maintain a stable light emitting characteristic over a long period of time. The composition comprises (A) an epoxy resin containing at least two glycidyl groups in each molecule thereof and having a molecular weight of 200 to 7000, (B) an epoxy resin containing at least one glycidyl group in each molecule thereof and having a molecular weight of 20000 to 100000, (C) a latent acid photo catalyst adapted to be activated and produce an acid upon being irradiated with energy beam, and (D) a silane coupling agent containing a glycidyl group in each molecule thereof, the composition exhibiting non-fluidity at 25° C., but exhibiting fluidity in a temperature range of 50° to 100° C.

The invention discloses a thermosetting resin composition, which is characterized by comprising the following components in part by weight: 8 to 80 parts of allyl modified bismaleimide resin prepolymer, 15 to 60 parts of cyanate resin and 5 to 40 parts of halogen-free epoxy resin, wherein the allyl modified bismaleimide resin prepolymer is prepared by reacting bismaleimide resin with an allylcompound at the temperature of between 110 and 160DEG C for 20 to 100 minutes, and a weight ratio of the bismaleimide resin to the allylcompound is 100:(30-120). The composition can be used for preparing a prepreg and a laminated board. The composition and the laminated board have excellent humidity resistance, high heat resistance, low water absorption rate, high modulus, lower dielectric constant and dielectric loss, and good processing toughness, and can realize halogen-free flame retardancy.

The present invention discloses a hot-wet resistant and aging resistant dual-component condensation type room temperature curing silicone rubber. According to the rubber, a epoxy group-containing compound and an amino silane coupling agent compound are respectively added to a component A and a component B of the dual-component condensation type room temperature curing silicone rubber; treatments of mixing and curing are performed to form a elastomer, wherein the elastomer provides excellent adhesion for the substrate, and retains good mechanical property and good adhesion property under the hot-wet environment. According to the present invention, during the rubber applying process, the component A and the component B of the dual-component condensation type room temperature curing siliconerubber are uniformly mixed according to a weight ratio or a volume ratio automatically calculated by equipment, then bubbles are removed, and the curing treatment is performed for a plurality of hours or days at the room temperature to form the elastomer, wherein the elastomer has good mechanical property and good adhesion property. Compared to the silicone rubber without addition of the epoxy group-containing compound, the silicone rubber of the present invention has significant hot-wet resistance.

The invention discloses a thermosetting resin composition for an integrated circuit. The thermosetting resin composition comprises (a) 10-60 parts of an allyl modified bismaleimide resin prepolymer, (b) 10-40 parts of an anhydride compound, (c) 10-50 parts of benzoxazine resin, (d) 5-50 parts of epoxy resin, (e) 5-50 parts of a fire retardant, (f) 0-5 parts of a curing accelerator and (g) 0-35 parts of inorganic stuffing, wherein the number-average molecular weight of the allyl modified bismaleimide resin prepolymer is 1500-8000 g / mol. The resin composition provided by the invention keeps high heat resistance and high Tg characteristic of the allyl modified bismaleimide resin prepolymer, and achieves UL94V-0 level in halogen-free flame retardant aspect on the basis of low phosphorus content, and simultaneously, has low dielectric constant of the anhydride; and therefore, the resin composition is capable of meeting the requirements of the production process of high-performance printed circuit boards such as a high-density interconnected integrated circuit package.

The invention discloses a modified hot setting resin and a preparation method thereof. In parts by weight, the modified hot setting resin is obtained by evenly mixing 100 parts of hot setting resin, 0-100 parts of curing agent, 0-1 part of curing catalyzer, and 1-100 parts of hyperbranched silicon resin containing active functional groups at the temperature of 30-200 DEG C. The modified hot setting resin has high storage stability, processability and reactiveness and sufficiently integrates the performance advantages of hyperbranched polymer and polysiloxane, and thereby the obtained modified hot setting resin has high tenacity, more prominent thermostability and excellent dielectrical property as well as damp heat resistance. The preparation method of the modified hot setting resin has wide applicability, simple operating process and easy molding.

The invention discloses an environmentally-friendly barium-free thixotropic antirust oil, which is characterized by comprising the following components in percentage by weight: antirusting agent 4.0-25.0, thixotropic agent 0.1-5.0, antioxidant 0.1-3.0 and base oil 72.0-94.0. The preparation method of the environmentally-friendly barium-free thixotropic antirust oil comprises: firstly, adding the base oil into a reaction kettle, stirring the base oil, heating the base oil to 110 to 120 DEG C, adding the antirusting agent, stirring the mixture for continuous dehydration for 1 hour, and cooling the mixture to 50 to 60 DEG C; and secondly, adding the antioxidant, stirring the mixture for 3 hours at a constant temperature of 50 to 60 DEG C, adding the thixotropic agent, stirring the mixture for1 hour at 50 to 60 DEG C, cooling the resulting product to 40 DEG C, filtering the resulting product and discharging the resulting product. For obtaining antirust oil films that are insusceptible toflow and free from heavy metal barium, the antirust oil selects a proper barium-free corrosion inhibiter to ensure excellent antirust performance besides the thixotropic agent added for quickly forming stable oil films of antirust oil.

The invention relates to an epoxy resin composition as well as a prepreg and a copper-foil-clad laminated board prepared by using the same. The epoxy resin composition comprises the following essential components: (A) epoxy resin containing a naphthol structure, (B) an active ester serving as a curing agent, and (C) a curing accelerant. Because epoxy resin at least contains the naphthol structure in the molecular structure, the epoxy resin composition provided by the invention has higher functionality degree and high glass transition temperature; at the same time, the naphthol group structure is introduced to the molecular structure, thus the cured product has low water absorptivity and low expansion coefficient; due to the active ester serving as the curing agent, the advantages that the a polar group is not generated during the reaction between the active ester and epoxy, thus the dielectric properties are excellent and moisture and heat resistance are good are fully exerted; and in addition, because of the epoxy resin containing the special naphthol structure, the hydroscopicity of the resin cured product is further reduced and the dielectric loss value of the cured product is lowered. The prepreg and the copper-foil-clad laminated board provided by the invention have excellent dielectric properties, moisture and heat resistance and high glass transition temperature.

The invention discloses a thermosetting resin composition which comprises epoxy resins except brominated epoxy resin, an styrene maleic anhydride copolymer and an additive flame retardant, and further comprises an active ester. The thermosetting resin composition can be used for preparing resin sheet materials, resin compound metal copper foils, prepregs, laminates, copper clad laminates, printed circuit boards, etc. The thermosetting resin composition substantially reduces probability of delamination of PCB substrate, overcomes disadvantages of deterioration of system dielectric properties due to introduction of tetrabromobisphenol A, and has advantages of good heat stability and heat and humidity resistance, low dielectric constant and dielectric loss tangent, and good flame resistance.

Disclosed is a heat ray reflective film having a single layer structure, which has high heat ray reflectivity, can relatively control visible light absorption and visible light reflection and has excellent heat stability. Also disclosed is a heat ray reflective laminate which has high environmental durability and is suitable as a window material for buildings or automobiles.A heat ray reflective laminate which is a laminate comprising a transparent substrate and a heat ray reflective layer and which has a solar reflectance of at least 15% as measured from the side containing the heat ray reflective layer, wherein the heat ray reflective layer comprises a binder resin containing a hydrophilic group other than an N-pyrrolidonyl group, and a metal, and the heat ray reflective layer has a layer thickness of at most 100 nm.

The invention relates to a solar cell packaging EVA adhesive film capable of resisting heat, humidity, ultraviolet light and aging, which comprises the following materials by weight portions: 100 portions of copolymer of ethylene vinyl acetate, 0.8-1.4 portions of crosslink curing agent, 0.05-0.15 portion of crosslink curing accelerator, 0.2-0.6 portion of tackifier, 0.1-0.5 portion of antioxidant, 0.05-0.25 portion of ultraviolet light stabilizer and 0.1-0.3 portion of ultraviolet light absorbent, wherein the crosslink curing agent is tert butyl peroxy 2-ethyl hexyl carbonate; the crosslink curing accelerator is triallyl isocyanurate; the tackifier is r-glycidyl ether oxy-propylltrimethoxysilane; the antioxidant is one or two selected from the group consisting of bis(2,4-dicumylphenyl)pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris(nonyl phenyl)phosphate and tris(2,4-butylphenyl)phosphate; and ultraviolet light absorbent is gas phase silicon dioxide. The solar cell packaging EVA adhesive film can resist high temperature of 85 DEG C, humidity of 85 percent, ultraviolet light and thermal oxidative aging.

A method for producing a conductive composite includes coating a composition (B) containing a dispersing agent (A) having a hydroxyl group in the molecule and a conductive material on a substrate, and coating a liquid containing a compound (C) represented by the formula (I) below and / or a hydrolysate of the compound (C) on a surface coated with the composition (B):(R1)mMXn-m   (1).

The present invention provides a fluorylbis-benzoxazoly monomer and a preparation method thereof. In a container with a mixer, a cooling pipe and a thermometer, formaldehyde solution of 37 percent and an organic solvent are added according to a weight ratio of (1 to 4) to 1, primary amine is added into the formaldehyde solution at the temperature between 5 DEG C and 10 DEG C, the reaction solution is continuously mixed for reaction for 1 to 4 hours and heated to be between 70 DEG C and 120 DEG C, an organic solvent with dissolved bisphenol fluorine is added, weight percentage of the bisphenol fluorine in the organic solvent is 20 percent to 50 percent, the molar ratio of the bisphenol fluorine and the primary amine is (1 to 2) to 3; the reaction continues to last for 4 to 10 hours at the temperature between 70 DEG C and 120 DEG C, and ultimately the fluorylbis-benzoxazoly monomer can be acquired through post processing. Because of the fluorine structure, the rigidity of molecular chains of the product can be enhanced, and the glass-transition temperature of resin can be improved; because of the enhanced nonpolarity of molecules, the hygroscopicity of the resin is lowered, thereby improving the wet-hot aging performance of the resin is greatly improved.

The invention provides a fluosilicic modification water-soluble acrylic resin dispersion and an application thereof. The dispersion is prepared from 20-50% of non-functional (methyl) acrylic ester, 5-35% of fluorinated acrylic ester monomer, 5-15% of carboxyl group-containing alkene monomer, less than or equal to 15% of vinyl monomer, 2-20% of (methyl) hydroxyl acrylate, 1-5% of organic silicon modified monomer, 15-30% of low carbon alcohol, 0.5-4% of inhibitor and 0.1-1.8% of molecular regulator according to a radical solution polymerization method. Based on solid parts, the acidic value of the dispersion is 20-100 mg KOH / g; the glass-transition temperature is 5-40 DEG C; the dispersion has a good appearance and dispersion stability as well as good water diluent property; a film obtained by cross-linking and curing a polycarbodiimide cross-linking agent and the dispersion has excellent water tolerance, solvent tolerance, high temperature tolerance, smooth property, stain tolerance and humidity resistance; the adhesion and hardness are improved; and the dispersion has strong practicable value and can be used for substrates such as wooden wares, metals, plastics and the like.

The present invention discloses a thermosetting resin composition and a method for manufacturing a prepreg and a laminated board by using the thermosetting resin composition. The thermosetting resin composition is prepared by dispersing the following components in an organic solvent, wherein the components comprise, by weight, 10-80 parts of an epoxy resin, 10-60 parts of cyanate, 10-60 parts of bismaleimide, 10-50 parts of polyphenylene oxide, 0.01-1.0 part of a curing accelerator, 1-40 parts of a fire retardation agent, and 0-100 parts of an inorganic filler, and the solid content of the resin composition is 30-70 wt%. The prepared prepreg and the metal foil-clad laminated board have characteristics of good heat resistance, good wet heat resistance, high glass-transition temperature, low water absorption rate, low dielectric constant, low dielectric loss factor and the like.

The invention discloses a nuclear power halogen-free, low-smoke and flame-retardant cable sheath material with high elongation and long service life and a preparation method thereof, and belongs to the technical field of materials for electric wires and cables. The cable sheath material is characterized by consisting of the following components in parts by weight: 100 parts of a resin base material, 100 to 150 parts of composite flame retardant, 5 to 25 parts of coordinated flame retardant, 3 to 20 parts of a first interface compatilizer, 1.5 to 4 parts of composite antioxidant, and 2 to 5 parts of lubricating agent. The cable sheath material has high mechanical property, particularly elongation at break, good thermo-oxidative aging resistance and long service life; the inherent triangular contradiction of electric, mechanical and flame-retardant properties of the halogen-free, low-smoke and flame-retardant cable sheath material can be effectively solved; meanwhile, the cable sheath material is excellent in processing performance, facilitates extrusion molding, and is scientific and reasonable in formula and proportion and advanced in process.

The invention belongs to the technical field of copper clad laminates and particularly relates to a resin composition, prepreg using the resin composition and a laminate. The resin composition contains the ingredients in percentage by weight: 15-55% of amine modified bismaleimide (BMI), 10-45% of benzoxazine resin and 0-75% of epoxy resin. According to the resin composition, through further reaction of benzoxazine (BOZ) and amine modified bismaleimide (BMI), performance advantages of two kinds of high-performance resin, namely BMI and BOZ, are excellently exerted, so that the prepreg and the copper clad laminates, manufactured from the resin composition, have the properties of high Tg, relatively high peeling strength, relatively low CTE, relatively low water absorbing capacity, relatively low dielectric loss, relatively high elastic modulus high-temperature retention rate, relatively good resistance to hot and damp and the like, and reach a flame-retardant level UL94-V0.

The invention relates to a thermosetting resin composition which comprises (A) epoxy resin with a naphthol structure on a molecular main chain; (B) cyanate ester compound or / and cyanate ester prepolymer; and (C) phosphonate or / and phosphonate-carbonic ester copolymer. The thermosetting resin composition provided by the invention is low in dielectric constant and dielectric loss tangent, a prepreg and a copper clad laminate prepared by using the above thermosetting resin composition has excellent dielectrical property, humidity resistant property and craft processability, and the fire resistance is up to the UL94 V-0 level.

The invention provides a thermosetting resin composition comprising a prepolymer of a diallyl compound and a maleimide compound, wherein the structural formula of the diallyl compound is shown as a formula (1) described in the specification; R1 is -C (CH3)2, -C (CF3)2, -SO2, -CH (CH3), -CH2 or an oxygen atom; R2 and R3 are same or different aliphatic hydrocarbon with the carbon number below 10 or aromatic hydrocarbon with the carbon number below 30; the R2 and the R3 contain no allyl group. The thermosetting resin composition has the advantages of good heat stability and heat and humidity resistance, low dielectric constant and dielectric loss angle tangent and excellent process machinability. The embodiment of the invention further provides applications of the thermosetting resin composition to resin sheets, resin composite metal foils, prepregs, laminated boards, metal foil clad laminates and printed circuit boards.

The invention discloses a biodegradable resin composition. The composition consists of the following raw materials in part by weight: 95.0 to 99.9 parts of biodegradable homopolyester and biodegradable copolyester and 0.1 to 5.0 parts of auxiliary agent for controlling performance ageing rate, wherein a mass ratio of the biodegradable homopolyester to the biodegradable copolyester is 1:9-9:1; andthe auxiliary agent for controlling the performance ageing rate is a mixture of a chain extender, an anti-hydrolysis agent and an antioxidant. A preparation method of the biodegradable resin composition comprises the following steps of: mixing the raw materials according to a proportion, drying, stirring and extruding. The biodegradable resin composition has moderate biodegradation rate and high physical property and processability; the composition is properly adjusted according to different using requirements to meet various application fields of blow molding, extrusion, injection, spinning forming and the like; and the composition has a longer using or storage period under the usual application condition, and even can be applied to a high-temperature high-humidity application environment.

The invention provides a thermosetting resin composition, comprising a diallyl compound, wherein the structural formula of the diallyl compound is as shown in formula (1), wherein R1 is -C(CH3)2, -C(CF3)2, -SO2, -CH(CH3), -CH2 or oxygen atom; R2 and R3 are the same or different aliphatic chain alkyls or aromatic alkyls; and R2 and R3 contain no allyl group. The thermosetting resin composition are excellent in heat stability and humidity resistance, low in dielectric constant and dielectric loss angle tangent, and excellent in processability. The embodiment of the invention also provides applications of the thermosetting resin composition in a resin sheet, a resin compound metal foil, a prepreg, a laminated board, a metal foil covered laminated board and a printed circuit board.

The invention discloses a preparation method of copper clad plate and the method comprises the following steps: (1) adopting bismaleimide resin and allyl compound in a weight ratio of 100:40-100 to react at 110-160 DEG C for 10-120min and obtain prepolymer, cooling to room temperature after finishing the reaction, using acetone to prepare prepolymer solution; (2) adding 15-150 parts of epoxy resinwith phosphorous, 10-100 parts of compound curing agent and 0-5 parts of curing accelerator in the solution obtained in the step 1, stirring evenly to obtain a glue solution, selecting a flat E-glassfibic cloth, coating the glue solution evenly on the glassfibic cloth, then roasting to prepare B-stage prepreg; (3) cutting the B-stage prepreg to proper size according to the size of a pressing machine, overlying five prepregs while placing two high impact copper foils with the same size separately on the top and bottom of the prepregs, placing the prepregs with copper foils in a vacuum hot pressing machine to press and obtaining the copper clad plate. The obtained copper clad plate can meet the demand for halogen-free and flame resistance, the heat resistance and humidity resistance are excellent, and the low dielectric loss and pressing toughness are good.

A transparent conductive film comprising: an organic polymer film substrate; an Al2O3 thin film formed on the organic polymer film substrate; and a ZnO-based thin film that is formed on the Al2O3 thin film and comprises ZnO doped with at least one of Ga and Al. The transparent conductive film has a low resistance value, even when the thickness of the ZnO-based thin film is reduced (particularly to about 150 nm or less), and shows a low rate of resistance change even in a hot and humid environment.

The invention provides a dampness-heat-resistant high-reliability epoxy conductive silver adhesive as well as a preparation method and an application thereof. The dampness-heat-resistant high-reliability epoxy conductive silver adhesive is prepared by adopting the following raw materials: 65 to 85 percent of metal silver powder, 5.0 to 30 percent of epoxy resin, 1 to 15 percent of active heterocyclic compound having a triazine structure, 0.5 to 10 percent of acrylic resin, 1.0 to 3.5 percent of curing agent, 0.05 to 1.5 percent of accelerant and 0.01 to 3 percent of functional additives. The invention also provides a preparation method and an application of the conductive silver adhesive. The prepared conductive silver adhesive has good conduction performance, mechanical performance, adhesion performance and dampness and heat resistance, can effectively improve the problem that the existing conductive silver adhesive is poor in dampness and heat resistance and has a red zone during the aging process and also can remarkably improve the reliability of a packing device and product.

The invention relates to a thermosetting resin composition and a prepreg and a laminate for printed circuits thereby. The thermosetting resin composition comprises at least an epoxy resin with a component being the structural formula (I) and a curing agent. The molecular structure of the epoxy resin composition of the invention contains the low-polarity styrene structure, therefore, the dielectricproperty of the resin is optimized. The dielectric constant and the dielectric loss angle tangent are reduced compared with those of the common epoxy resins. The prepreg obtained by coating the resincomposition on the substrates and the laminate manufactured by laminating the prepreg simultaneously have the characteristics of low dielectric constant, low dielectric dissipation factors, good heatresistance, good dip soldering resistance, good moisture resistance, good humidity resistance and good cohesiveness with copper foils. The resin composition of the invention can be also used for manufacturing the resin sheets, resin composition copper foils, the laminate and the printed circuit boards. R is (a), and n and m are natural numbers.

The invention provides a dealcoholized organosilicon sealant with damp-heat resistance and stable storage. The dealcoholized organosilicon sealant is characterized in that the organosilicon sealant comprises the following components according to parts by weight: 100 parts of alpha, omega-dihydroxy polydimethylsiloxane, 1-20 parts of mixed crosslinking agent, 1-20 parts of titanate catalyst, 0-300 parts of filler, 0-200 parts of low molecular weight silicone oil and 0-10 parts of tackifier. The invention further provides a preparation method for the dealcoholized organosilicon sealant, which is characterized in that: as titanate is selected as the catalyst and the mixed crosslinking agent is used, the storing and processing performances are improved; with excellent mechanical property, good damp-heat resistance and high storage stability, the obtained sealant is particularly applicable to adhesive bonding and encapsulating of various electronic and electrical appliances.

This invention provides a sheet polarizer,including polyvinyl alcohols polarizing film, sticking agent layer separated from polyvinyl alcohols polarizing film through at least on face and overlapped with protect film. Said sticking agent layer is comprised of sticking agent components containing followed water solution. Said water solution contains acetyl modified PVA resin and glyoxylate indicated by formula (I) and has a pH valve ranged in 4-10. where, the content of acetyl modified PVA resin is 1-8%( percentage by weight) compared to the 100% water(percentage by weight), the weight ratio of acetyl modified PVA resin with the solid glyoxylate is in the range of 1:0.03-0.25. in formula (I) , M represents alkali metals or alkaline-earth metals, n represents valence mumber correspond to M, indicating 1 or 2. According to said sheet polarizer, sticking property together with warm water resistance between the polarizing film and the protect film are improved.

The invention discloses a resin composition which comprises the following solids by weight: (a) 100 parts of a bismaleimide resin prepolymer, (b) 5-80 parts of cyanate ester, (c) 0-50 parts of a flame retardant and (d) 0-65 parts of inorganic filler, wherein the bismaleimide resin prepolymer is obtained by carrying out reaction on an allyl compound and bismaleimide resin and the ratio of bismaleimide resin and allyl compound by weight is 100: (10-120). According to the resin composition disclosed by the invention, by adopting siloxane containing allyl at the tail end as a modifier of bismaleimide resin and limiting the content of siloxane in the modifier, unreacted siloxane resin is not generated in reaction, so that the advantages and characteristics of siloxane resin can be fully exerted and the interlaminar adhesive force at the high temperature is greatly improved. Moreover, the thermal expansion properties of the solids are optimized, so that the resin composition satisfies the requirements on high precision electronic substrate materials.

The invention discloses a resin composition for a high-frequency high-speed substrate. Measured according to solid weights, the resin composition comprises the following components: 10-50 parts of cyanate ester resin (a), 10-40 parts of anhydride compounds (b), 5-50 parts of benzoxazine resin (c), 5-50 parts of epoxy resin (d), 5-50 parts of flame retardant (e), 0-5 parts of curing accelerator (f) and 0-80 parts of inorganic filler (g). The resin composition disclosed by the invention has high moisture and heat resistance, high glass transition temperature as well as lower dielectric constant and dielectric loss tangent value, and can be well applied to the fields such as high-frequency, high-speed and high-density interconnection and the like; and a laminated board made of the resin composition has excellent moisture and heat resistance and good bonding power.

The invention discloses a rust-proof soft film composition and a preparation method thereof, belonging to the technical field of metal protection and particularly relating to a metal rust preventing technology. The rust-proof soft film composition disclosed by the invention comprises the following components in a formula in percentage by mass: 40-70 of film forming agent, 2-10 of corrosion and rust inhibitor, 1-5 of vapor phase inhibitor, 4-10 of microcapsule antirust agent, 0-10 of pigment, 1-3 of rheological agent, 0.2-1.0 of defoaming agent and 10-25 of solvent. The rust-proof soft film composition disclosed by the invention has an excellent rust-proof effect and an excellent self-repairing function; rust-proof gas volatilized by the film can meet the rust-proof requirements of inner and outer surfaces of workpieces with complex structures such as inner metal cavities, inner walls of pipelines, grooves and the like; when the rust-proof soft film is destroyed in a use process, a rust-proof core with an excellent self-repairing function of the microcapsule antirust agent can be automatically repaired, so that the condition that the rust-proof film is invalid in advance because of being destroyed is avoided, and the protection time of a protective film is prolonged; and the rust-proof soft film composition can comprehensively meet the requirement for metal rust-proof protection under severe environments such as outdoor sun and rain, sand-dust and the like.

The invention provides a powdery mixture of a multi-component tunnel fire retardant coating, which is prepared from 582 resin, Portland cement, sepiolite, ammonium dichromate, light calcium carbonate, aluminum silicate, fly ash hollow floating beads, wollastonite powder, argil, cellulose ether, a concrete expanding agent, tin oxide and polypropylene fiber. The powdery mixture is prepared by throwing the fire retardant coating into a V-shaped forced mixer according to the proportion of the components; stirring the mixture for 10 to 15 minutes to prepare the powdery mixture; stirring water and the fire retardant coating powder in a weight ratio of 0.8-0.85 into thick paste; and spraying a tunnel from the waist to the top with spray painting equipment to reach the predetermined thickness.