JP2006503958A - Continuous process for producing hot melt adhesive compositions - Google Patents

Abstract

A continuous process for making a moisture curable hot melt adhesive composition includes feeding an organopolysiloxane, silicone resin, silane crosslinker, catalyst, and solvent to the extruder and removing volatile components. By using a continuous process, the content of non-volatile components can be adjusted and a consistent product can be produced. When exposed to moisture, the hot melt composition cures and provides adhesion between the two substrates.

Description

(Cross-reference)
This application claims priority based on US Provisional Patent Application No. 60 / 420,575, the entirety of which is incorporated herein by reference.

(Field of Invention)
The present invention relates to a continuous process for producing a moisture curable hot melt adhesive composition. The method includes feeding a mixture of organopolysiloxane, silicone resin, silane crosslinker, and solvent to an extruder and removing volatile components. By using a continuous process, the content of non-volatile components can be adjusted and a consistent product can be produced. When exposed to moisture, the hot melt adhesive composition cures and provides adhesion between at least two substrates.

(Background technology)
Moisture curable organosiloxane compositions are used in many applications, such as sealant compositions that can be applied to joints between elements and cured to provide an elastic seal between the elements. . These compositions cure at room temperature, yet sealants for sealing highway joints, joints of articles such as vehicle headlights, and building joints, and for glass glazing applications It is particularly attractive for use as a composition because the special heating or other curing conditions normally required to form a seal of the desired quality are not required.

  Many moisture curable organosiloxane compositions have been proposed and are capable of reacting with the polyorganosiloxane to form a crosslinked network that is at least one substantially linear polyorganosiloxane containing at least two silanol groups. It is usually made from a cross-linking agent capable of These compositions cure by a condensation reaction promoted by moisture.

  The crosslinking agent in the moisture curable organosiloxane composition is usually selected from polyfunctional silanes that readily hydrolyze. Commonly used crosslinking agents are triacetoxysilanes, trialkoxysilanes, triaminosilanes, and trioximosilanes. The condensation reaction is considered to proceed through, for example, the capping of polyorganosiloxane by dialkoxyalkylsilyl group and the subsequent interaction of the alkoxy group and / or silanol group of the end cap resulting in a crosslinked structure. It is done.

  Some curing of the above composition during manufacture and storage is acceptable, but long before it is applied at the intended work site, where it is intended to cure under the influence of atmospheric moisture It is important that curing does not proceed. Thus, the exposure of the composition to moisture should be kept within a certain acceptable low range from batch to batch during manufacture and storage, otherwise the composition has its intended purpose. However, it will be hardened to a practical level.

  Moisture curable compositions based on organosilicon compounds usually contain finely dispersed fillers. Commonly used fillers are those that strengthen the cured material, reduce the cost of the product, or otherwise provide the desired combination of properties.

  Typical fillers include, but are not limited to, high surface area silica, quartz powder, iron oxide, zinc oxide, carbon black, calcium carbonate, and diatomaceous earth. Moisture curable organosiloxane compositions can be made using a batch or continuous process, in which filler and polyorganosiloxane are mixed together, to which the crosslinker and catalyst are added and obtained. The resulting composition is then packaged in a container, such as a cartridge, which is then hermetically sealed to prevent moisture ingress.

Silicone adhesives (also referred to herein as PSA) typically have at least two major components: a linear siloxane polymer, as well as essentially triorganosiloxane units (ie R ₃ SiO _1/2). Unit, where R represents a monovalent organic group) and a tackifying resin consisting of silicate units (ie, SiO _4/2 units). In addition to the two components, some silicone PSA compositions include some crosslinking means (eg, peroxide or hydrosilation curing systems) to optimize various properties of the final adhesive product. . In view of the high viscosity provided by the polymer components, these PSA compositions are typically dispersed in an organic solvent for ease of application. Some of these PSAs contain reactive groups that allow the composition to cure upon exposure to moisture. Similar combinations can be incorporated into the coating composition when the resin and polymer ratios described above, as well as other parameters, are adjusted. Under certain other conditions, hot melt PSA can be obtained.

(Summary of invention)
The present invention relates to a continuous process for producing a moisture curable hot melt silicone adhesive composition. This process involves mixing an organopolysiloxane, a silicone resin, a silane crosslinker, and a solvent; feeding the combination to an extruder to remove volatile components; and 95% by weight or more of non-volatile components Recovering a hot melt adhesive composition having a content. This manufacturing method is advantageous in terms of cost, convenience, and product consistency.

(Detailed Description of the Invention)
The present invention relates to a continuous process for producing a hot melt adhesive composition. This process involves mixing an organopolysiloxane, a silicone resin, a silane crosslinker, and a solvent; feeding the combination to an extruder to remove volatile components; and 95% by weight or more of non-volatile components Recovering a hot melt adhesive composition having a content.

The silicone resin useful in the present invention comprises a monofunctional unit represented by R ¹ ₃ SiO _1/2 and a tetrafunctional unit represented by SiO _4/2 . R ¹ represents a substituted or unsubstituted monovalent hydrocarbon residue. This type of silicone resin is well known in the art as one of the components present in organosiloxane compositions used as adhesives.

  The silicone resin is soluble in liquid hydrocarbons such as benzene, toluene, xylene, heptane, and the like, or liquid organosilicon compounds such as low viscosity cyclic and linear polydiorganosiloxanes.

In R ¹ ₃ SiO _1/2 units, R ¹ is a monovalent hydrocarbon residue typically containing 20 or fewer carbon atoms, typically 1 to 10 carbon atoms. Examples of hydrocarbon residues suitable as R ¹ include alkyl residues such as methyl, ethyl, propyl, pentyl, octyl, undecyl, and octadecyl; alkenyl residues such as vinyl, allyl, and 5-hexenyl; Alicyclic residues such as cyclohexyl and cyclohexenylethyl; and aryl residues such as phenyl, tolyl, xylyl, benzyl, and 2-phenylethyl are included. Non-reactive substituents that may be present on R ¹ include, but are not limited to, halogen and cyano. Exemplary substituted hydrocarbon residues that may be represented by R ¹ include, but are not limited to, chloromethyl and 3,3,3-trifluoropropyl.

At least one third or at least two thirds of the R ¹ residues in the R ¹ ₃ SiO _1/2 unit are methyl residues. Examples of R ¹ ₃ SiO _1/2 units include Me ₃ SiO _1/2 , PhMe ₂ SiO _1/2 , and Me ₂ ViSiO _1/2 (where Me, Ph, and Vi are methyl, phenyl, And vinyl)), but is not limited thereto. The said silicone resin can contain 2 or more types of these units.

The molar ratio of R ¹ ₃ SiO _1/2 units and SiO _4/2 units in the silicone resin is typically 0.5 / 1 to 1.5 / 1, preferably 0.6 / 1 to 0.00. 9/1. These molar ratios are conveniently the Si ²⁹ n. m. r. Measured by spectroscopy. This approach involves the R ¹ ₃ SiO _1/2 (“M”) units and SiO _4/2 (SiO _2/2 units derived from the silicone resin and neopentamer (Si (Me ₃ SiO) ₄ ) present in the original silicone resin. The “Q”) unit concentration can be determined quantitatively, and in addition, the total hydroxyl content of the silicone resin can be determined quantitatively.

For purposes of the present invention, the above R ¹ ₃ SiO _1/2 to SiO _4/2 ratio can be expressed as {M (resin) + M (neopentamer)} / {Q (resin) + Q (neopentamer)}. Represents the ratio of the total number of triorganosiloxy groups of the resin and neopentamer moiety to the total number of silicate groups of the resin and neopentamer moiety of the silicone resin.

The silicone resin comprises 2.0% by weight or less, or 0.7% by weight or less, or 0.3% by weight or less of terminal units represented by the formula XSiO _3/2 , where X is hydroxyl or Hydrolyzable groups such as alkoxy such as methoxy and ethoxy; alkenyloxy such as isopropenyloxy; ketoximo such as methylethylketoximo; carboxy such as acetoxy; amidoxy such as acetamidoxy; and aminoxy such as N, N-dimethylaminoxy Represents. The concentration of silanol groups present in the silicone resin can be determined using Fourier transform infrared spectroscopy (FTIR).

The number average molecular weight M _n required to achieve the desired flow characteristics (flow characteristics) of the silicone resin is represented by the molecular weight of the silicone resin and R ¹ and is a hydrocarbon residue present in this component. Depends on at least some extent. M _n used in the present specification represents a molecular weight measured using gel permeation chromatography when a peak appearing by the neopentamer is excluded from the measurement. The _Mn of the silicone resin is typically greater than 3000 and more typically 4500-7500. Typically, heat resistance above 150 ° C. (ie, the ability of the adhesive to maintain adhesion at high temperatures) becomes significant when M _n is greater than 3000.

  The silicone resin can be prepared by any suitable method. This type of silicone resin has been reportedly produced by co-hydrolysis of the corresponding silanes or by silica hydrosol capping methods known in the art. The silicone resins are preferably those of Daudt et al., US Pat. No. 2,676,182; Rivers-Farrell et al., US Pat. No. 4,611,042; and Butler et al., US Pat. No. 4,774,310. Manufactured by a silica hydrosol capping method.

The intermediates used to make the silicone resin are typically triorganosilanes of the formula R ¹ ₃ SiX ′ (where X ′ represents a hydrolyzable group), and four hydrolysables Either a silane having a group (eg, halogen, alkoxy, or hydroxyl) or an alkali metal silicate (eg, sodium silicate).

The silicon-bonded hydroxyl group (that is, HOR ¹ SiO _1/2 or HOSiO _3/2 group) in the silicone resin is 0.7% by mass or less, or 0.3% by mass or less of the total mass of the silicone resin. Preferably there is. Silicon-bonded hydroxyl groups formed during the production of the silicone resin can be converted to trihydrocarbylsiloxy groups or hydrolyzable by reacting the silicone resin with silane, disiloxane, or disilazane containing appropriate end groups. Converted to the base. Silanes containing hydrolyzable groups are typically added in excess of the amount required to react with the silicon-bonded hydroxyl groups of the silicone resin.

The organopolysiloxane useful herein comprises a difunctional unit of formula R ² R ³ SiO and a terminal unit of formula R ⁴ _a X ′ _3-a SiG—, wherein R ² is an alkoxy group or a monovalent R ³ is an unsubstituted or substituted monovalent hydrocarbon residue; R ⁴ is an aminoalkyl or R ¹ group; X ′ is a hydrolyzable group; G is a silicon atom of the terminal unit; A divalent group linked to another silicon atom, and a is 0 or 1; The organopolysiloxane can optionally contain up to about 20% of trifunctional units of the formula R ³ SiO _{3/2 based on} the total, where R ³ is as already described. At least 50%, typically at least 80% of the residues represented by R ² and R ³ of the R ² R ³ SiO unit are lower alkyl, such as methyl.

The terminal unit present in the organopolysiloxane is represented by the formula R ⁴ _a X ′ _3-a SiG—, where X ′ is a hydrolyzable group, R ⁴ is aminoalkyl or R ¹ , and G is a terminal unit. A divalent group linking a silicon atom to another silicon atom, and a is 0 or 1. Typically, the organopolysiloxane contains two or more hydrolyzable groups (X ′) per molecule to form a crosslinked product. Typical hydrolyzable groups represented by X ′ include alkoxy such as hydroxy, methoxy and ethoxy, alkenyloxy such as isopropenyloxy, ketoximo such as methylethylketoximo, carboxy such as acetoxy, amidoxy such as acetamidoxy, And aminoxy such as N, N-dimethylaminoxy, but are not limited thereto.

In the above terminal groups, when a is 0, the group represented by X ′ can be alkoxy, ketoximo, alkenyloxy, carboxy, aminoxy, or amidoxy. When a is 1, X ′ is typically alkoxy and R ⁵ is alkyl, such as methyl or ethyl, or aminoalkyl, such as aminopropyl or 3- (2-aminoethylamino) propyl. The amino moiety of the aminoalkyl residue can be primary, secondary, or tertiary.

In the above terminal unit formula, G is a divalent group or atom that is stable to hydrolysis. “Stable to hydrolysis” means that it is not hydrolysable, so that the terminal unit is not removed while the composition is cured, and the curing reaction is not adversely affected. Hydrolytically stable linking groups represented by G include hydrocarbylene containing one or more heteroatoms selected from hydrocarbylene such as oxygen, alkylene and phenylene, oxygen, nitrogen, and sulfur. , And combinations of these linking groups. G represents — (OSiMe ₂ ) CH ₂ CH ₂ —, — (CH ₂ CH ₂ SiMe ₂ ) (OSiMe ₂ ) CH ₂ CH ₂ —, — (CH ₂ CH ₂ SiMe ₂ ) O—, (CH ₂ CH ₂ Silaalkylene linking groups such as SiMe ₂ ) OSiMe ₂ ) O—, — (CH ₂ CH ₂ SiMe ₂ ) CH ₂ CH ₂ —, and —CH ₂ CH ₂ —, and siloxane linking groups such as — (OSiMe ₂ ) O—. Or, more preferably, an oxygen atom.

Specific examples of preferred terminal units are (MeO) ₃ SiCH ₂ CH ₂ —, (MeO) ₃ SiO—, Me (MeO) ₂ SiO—, H ₂ NCH ₂ CH ₂ N (H) (CH ₂ ) ₃ SiO— _{, (EtO) 3 SiO -,} (MeO) 3 SiCH 2 CH 2 SiMeCH 2 SiMeCH 2 CH 2 SiMe 2 O-, Me 2 NOSiO-, MeC (O) N (H) SiO-, and _CH 2 = C _{(CH 3} ) including, but not limited to, OSiO-. In these formulas, M represents methyl and Et represents ethyl.

When X ′ contains an alkoxy group, it is preferable to separate this X ′ group from the nearest siloxane unit by an alkylene residue such as ethylene. For ^{_{example, R 4 a X '3-}} a SiG- _may be a _{O- (MeO) 3 SiCH 2 CH} 2 Si (Me 2). Methods for converting alkoxy groups to trialkoxysilylalkyl groups are described in the prior art. For example, a moisture-reactive group having the formula (MeO) ₃ SiO— and Me (MeO) ₂ SiO— can be converted to a silanol-terminated polyorganosiloxane by a compound having the formula (MeO) ₄ Si and Me (MeO) ₃ Si, respectively. Can be introduced. Instead, when the polyorganosiloxane contains silanol groups or alkenyl groups such as vinyl, and platinum group metals or their compounds as hydrosilation reaction catalysts, they have the formula (MeO) ₃ SiH and Me (MeO) ₂ SiH, respectively. Compounds can be used. It will be appreciated that other hydrolyzable groups such as dialkylketoximo, alkenyloxy, and carboxy can be substituted for alkoxy groups.

  The organopolysiloxane used in the hot melt adhesive is preferably a polydimethylsiloxane containing three alkoximo groups or two alkoxy groups with either three alkoxy or ketoximo groups, alkyl or aminoalkyl residues. is there.

  The viscosity of the organopolysiloxane is in the range of 0.02 Pa · s to 100 Pa · s, typically 0.35 to about 60 Pa · s at 25 ° C.

  The silicone resin and organopolysiloxane are present in an amount that provides 55 to 75 resin solids based on the amount of silicone resin and organopolysiloxane. Larger amounts of resin can be used, but higher application temperatures are required to apply the moisture curable hot melt adhesive composition to the substrate.

The silane crosslinking agent is represented by the formula R ¹ _n SiZ _(4-n) , where R ¹ is as described above, and Z is cured by reacting with at least the end groups of the organopolysiloxane under environmental conditions. And n is 0, 1, or 2. Typically R ¹ is an alkyl and / or phenyl group. Suitable hydrolyzable groups represented by Z include, but are not limited to, alkoxy containing 1 to 4 carbon atoms, carboxy such as acetoxy, ketoximo such as methyl ethyl ketoximo, and aminooxy. When n = 2 in the silane crosslinker, the organopolysiloxane typically contains 3X ′ groups (eg, a = 0).

  Suitable silane crosslinkers are alkyl orthosilicates such as methyltrimethoxysilane, isobutyltrimethoxysilane, methyltris (methylethylketoximo) silane, methyltriethoxysilane, isobutyltriethoxysilane, methyltriacetoxysilane, and ethyl orthosilicate. Including, but not limited to.

  The amount of silane crosslinker used ranges from 0.5 to 100 parts per hundred (0.5 to 15 pph (parts per hundred)) based on the amount of silicone resin and polymer, typically Specifically, it is 8 parts per hundred (8 pph). If too much silane crosslinker is present, the green strength and / or the cure rate of the hot melt adhesive will be reduced. If the silane crosslinker is volatile, it may be necessary to use an excess to make 15 parts per hundred to 15 parts per hundred (1.5 pph to 15 pph) in the final hot melt adhesive composition. . One skilled in the art can determine the amount necessary to produce a composition having 1.5-15 pph.

  A titanate catalyst is typically used in the hot melt adhesive composition except where the organopolysiloxane and / or the silane crosslinker contains a ketoxime functional group. Titanate catalysts are organotitanium compounds such as tetrabutyl titanate and partial chelate derivatives of these salts with chelating agents such as acetoacetate and beta-diketones. The amount of titanate catalyst used is 0.01 to 100 parts per hundred (0.01 to 2 pph), typically 0.05 to 1 pph, based on the amount of resin and polymer. . If too much titanate catalyst is added, the composition will be poorly cured. In addition, as the amount of catalyst increases, the viscosity of the hot melt adhesive increases and higher melting temperatures are required to apply the material.

The hot melt adhesive composition may include 2 to 100 parts per hundred (0.05 to 2 pph) adhesion promoter based on resin and polymer. Adhesion promoters are known in the art, and typical silanes has the formula ^{_{R 5 c R 6 d Si (}} OR) 4- (c + d), substituted or wherein ^{R 5} is independently An unsubstituted monovalent hydrocarbon group having at least 3 carbon atoms, and R ⁶ comprises at least one SiC bonding group having an adhesion promoting group, such as an amino, epoxy, mercapto, or acrylate group; c is a value from 0 to 2, and d is either 1 or 2, and the sum of c + d is not greater than 3. The adhesion promoter can also be a partial condensate of the silane.

  The hot melt adhesive composition may include 0.1 to 40% by weight treated and / or untreated filler based on total adhesive. Examples of suitable fillers include calcium carbonate, fumed silica, silicate (silicate), metal oxide, metal hydroxide, carbon black, sulfate, or zirconate (zirconate).

  A solvent is typically used in producing the hot melt adhesive. The solvent aids fluidity and the introduction of the silicone resin and organopolysiloxane polymer. However, essentially all of the solvent is removed in a continuous process for the production of the hot melt adhesive. “Essentially” means that the hot melt adhesive composition contains no more than 0.05 to 5% by weight of solvent, preferably less than 0.5%, based on the weight of the hot melt adhesive. means. If too much solvent is present, the viscosity of the hot melt adhesive will be too low, impeding product performance.

  The solvent used here is a solvent that helps fluidize the components used in the manufacture of the hot melt adhesive, but essentially does not react with any components in the hot melt adhesive. Suitable solvents are organic solvents such as toluene, xylene, methylene chloride, naphtha mineral spirits, and low molecular weight siloxanes.

  The silicone resin, organopolysiloxane, silane crosslinker, solvent, and any optional components are fed to a continuous mixing device. The order of addition to the continuous mixing device is not critical to producing the hot melt adhesive composition. When the resin has typically more than 0.7% by weight of silanol, the silane crosslinks to allow any reaction to occur and the reaction products (ie, volatile components) to be removed. It is preferred to add the agent and / or catalyst and resin together. The continuous mixing device should be able to mix the components and include means for removing the solvent. Typically, an extruder is used, and more typically a twin screw extruder is used.

  When using an extruder, the components are fed into the extruder and heated to a temperature in the range of 50-250 ° C, alternatively 80-150 ° C. By heating the composition in an extruder, the viscosity is reduced and the components can be mixed well. Typically, in an extruder, the silicone resin and organopolysiloxane and solvent are fed into the apparatus. Silane crosslinkers and optional catalysts can also be added at this point, or they can be added further downstream in the apparatus after some mixing has taken place. The continuous steps of hot melt adhesive in a co-rotating twin screw extruder are described in T. Peitz, “Continuous Processing of Hot Melt Adhesives on Co-Rotating Twin Screw Extruder”, 1996 Hot Melt Symposium, p. 37-45 Has been.

  The solvent is removed during the continuous mixing process. Typically, a vacuum is applied to the continuous mixing device to facilitate removal of the solvent and any other volatile components present in the hot melt adhesive composition. A vacuum can be applied to the single or multiple stages of the continuous mixing device. It has been discovered that the use of multiple vacuum stages provides improved removal to the solvent. Since the silane crosslinking agent can be volatile, it is preferred to add the silane crosslinking agent after most of the solvent has been removed to prevent removal of the crosslinking agent along with the solvent.

  The hot melt adhesive composition can be used to bond at least two substrates together. Typically, the hot melt adhesive composition is used as a layer between two substrates, comprising a laminate of a first substrate, a cured hot melt adhesive, and a second substrate. produce. The laminated structure created here is not limited to these three layers. Additional layers of cured adhesive and substrate can be applied. The layer of hot melt adhesive composition in the laminate can be continuous or discontinuous. For example, a continuous layer can be used to form a laminate such as the window 100 shown below in FIG. Alternatively, the discontinuous layer can be used to form a laminate such as a housing 200 having a lid seal (seal) as shown below in FIG.

  Furthermore, there are no restrictions on the materials that can be used as the substrate. Suitable substrates to which the hot melt adhesive composition or their cured product can be applied include glass; metals such as aluminum, copper, gold, nickel, silicon, silver, stainless steel alloys, and titanium. Ceramic materials; engineering plastics such as epoxies, polycarbonates, poly (butylene terephthalate) resins, polyamide resins, and blends thereof such as polyamide resins and sold for example by The Dow Chemical Company of Midland, Michigan, USA; Including blends with syndiotactic polystyrene, acrylonitrile-butadiene-styrene, styrene-modified poly (phenylene oxide), poly (phenylene sulfide), vinyl esters, polyphthalamides, and polyimides Plastics; cellulosic substrates such as paper, cloth, and wood; and combinations thereof include, but are not limited to. If more than one substrate is used, it is not required that the substrate be made from the same material. For example, it is possible to form a laminate of glass and metal substrate, or glass and plastic substrate.

  One method for making the laminated structure is to apply a film of hot melt adhesive composition on the surface of the first substrate. The surface of the second substrate is then contacted with the hot melt adhesive composition and the first and second surfaces are pressed together. Conventional application methods suitable for use with molten materials include dipping, spraying, coextrusion, and spreading using heated doctor blades, draw down bars, and calendar rolls. It is not limited. Typically, the hot melt adhesive composition is applied by heating to a temperature of 80-150 ° C. and is applied by pressure through a hose. This type of device is known in the art and is commercially available. When exposed to moisture, the hot melt adhesive cures. The hot melt adhesive composition can be brought into moisture by contact with moisture in the air or by direct introduction of moisture, for example by contacting the laminate with steam or placing the laminate in a humidifier. Can be exposed.

  It is also possible to form a laminate by forming a film of the hot melt adhesive composition and then curing the film of the hot melt adhesive composition. The first surface of the cured film is brought into contact with the surface of the first substrate. The surface of the second substrate is then contacted with another surface of the cured film and the first and second surfaces are pressed together to form a laminate.

  Another alternative for producing a laminate is to apply a film of hot melt adhesive composition onto the surface of the first substrate. The hot melt adhesive composition is then cured by exposure to moisture to produce a cured film. The second substrate is then contacted with the cured film on the first substrate and the first and second surfaces are pressed together to form a laminate.

  Cured films prepared by curing hot melt adhesive compositions according to the present invention have found utility in many industries such as automotive, electrical, architecture, space, and medical. The cured film can provide an adhesive that resists adverse environments such as heat and moisture. For example, the cured film can be used as an insulating protective coating for substrates such as printed circuit boards and other substrates including electrical or electronic components.

  Various laminates can be made using the hot melt adhesive composition described above in accordance with the present invention. For example, the laminate can be a part of an air bag, an automobile interior, a window, or a lid sealing material. FIG. 1 shows a portion of a window made in accordance with the present invention. The window includes a sash 100 on which a film 101 of a hot melt adhesive composition is applied. A heat insulating glass unit 102 comprising two panes 103, 104 separated by a spacer 105 is applied to a film 101 of hot melt adhesive composition. The film 101 of the hot melt adhesive composition may be cured before being applied to the sash 100, after being applied to the sash 100, before being applied to the insulating glass unit 102, or after being applied to the insulating glass unit 102. it can. The two panes 103, 104 can be attached to the spacer 105 by a film 106 of hot melt adhesive composition. The film 106 of the hot melt adhesive composition is cured before application to the window glass 103 or 104, after application to the window glass 103 or 104, before application to the spacer 105, or after application to the spacer 105. be able to.

FIG. 2 shows a schematic diagram of a housing 200 for an electronic component 204 having a lid seal prepared in accordance with the present invention. The housing 200 is, for example,
(1) Applying the hot melt adhesive composition 201 described above as a container 202 on the frame of the first substrate shown here,
(2) Place the second substrate shown here as lid 203 on container 202 such that the end of lid 203 is in contact with hot melt adhesive composition 201, and (3) hot melt adhesive Curing the composition 201 to form a lid seal between the container 202 and the lid 203;
Can be made.

  One skilled in the art will appreciate that the hot melt adhesive composition can be first applied to the end of the lid 203 and then the lid 203 can be placed over the container 202. One skilled in the art can cure the hot melt adhesive composition 201 before, during, or after application to one or both of the substrates (lid 203 and container 202). You will understand. Alternatively, a hot melt adhesive composition or a hot melt adhesive made by curing a hot melt adhesive composition can be applied to the end of the lid after the lid is placed over the container. .

(Example)
material:
〔Silicone resin〕
Resin A: a xylene-soluble resin copolymer containing triorganosiloxy units and SiO ₂ units in a molar ratio of triorganosiloxy units of SiO ₂ units per mole 0.8 mole, wherein the triorganosiloxy units and trimethylsiloxy Dimethylvinylsiloxy and the copolymer contains 1.9% by weight vinyl residues and 1.5% by weight Si-bonded hydroxyl groups. This resin dissolves in xylene to give a 70 wt% solids solution.

Resin B: A xylene soluble resin copolymer containing triorganosiloxy units and SiO ₂ units in a molar ratio of 0.8. This resin is capped with trimethylsiloxy groups to give a resin with 0.7% by weight Si bonded hydroxyl groups. This resin is dissolved in xylene to give a 60 wt% solids solution.

[Organopolysiloxane]
Polymer A: —CH ₂ CH ₂ Si (OMe) A primarily linear polydimethylsiloxane polymer terminated with ₃ terminal groups and having an approximate viscosity of 70000 cs.

Polymer B: about 80% of the ends are terminated with —CH ₂ CH ₂ SiOSiCH ₂ CH ₂ Si (OMe) ₃ , the remaining ends are terminated with vinyl groups, and an approximately viscosity of 70,000 cs, mainly linear polydimethylsiloxane polymer.

  Polymer C: A primarily linear hydroxy-terminated polydimethylsiloxane liquid having a viscosity of 50 Pa · s at 25 ° C.

[Crosslinking agent]
Alkoxysilane A: i-BuSi (OMe) ₃ , isobutyltrimethoxysilane

Alkoxysilane B: MeSi (OMe) ₃ , methyltrimethoxysilane

  Oxime silane C: Methyltri (ethylmethylketoxime) silane

  Oxime silane D: Vinyl tri (methyl ethyl ketoxime) silane

[Optional ingredients]
Alkoxysilane C: NH ₂ CH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ Si (OMe) ₃

Alkoxysilane D: reaction mixture of 74 parts by weight (parts by weight (pbw)) of glycidoxypropyltrimethoxysilane and 26 pbw of aminopropyltrimethoxysilane, these silanes being mixed for 16 hours at room temperature What you put.
Calcium carbonate powder with an average particle size of 2 microns treated with CaCO ₃ -stearate. Available from Georgia Marble, Kennesaw GA, USA.

[Titanate catalyst]
Titanate catalyst A: Ti (OtBu) ₄ , tetra-tertiary butyl titanium

Titanate catalyst B: Ti (OBu) ₄ , tetra-n-butyltitanium

Titanate catalyst C: Ti (iOPr) ₂ (EAA) ₂ , diisopropyl-bis-ethyl acetoacetate titanium

  All these titanate catalysts are sold by DuPont of Deepwater NJ, USA.

  Tin catalyst D: Dibutyltin dilaurate

〔Test method〕
NVC: Nonvolatile content (NVC) was determined by placing about 1 g of hot melt adhesive in an aluminum weighing pan, heating to 110 ° C. for 16 hours, and recording mass change (remarks; Example 10 is 1 h / 150 ° C. condition).

  Viscosity: The equipment used is a Bohlin Instruments VOR Rheometer equipped with a Mitutoyo micrometer and a temperature controller. A parallel plate structure was used with a 1.5 mm gap between the plates. The test was performed in vibration mode using frequency = 1 Hz and amplitude = 25% (strain = 0.0518). The metal cartridge containing the hot melt was placed in an oven at 110 ° C. to obtain a sample for viscosity test. The sample was then placed between the plates and brought close together until a 1.5 mm gap was reached. During this process, the sample was heated up to 160 ° C. to 180 ° C. and excess sample was dropped from the side of the plate. Once the desired temperature and gap were reached, the sample was ramped from 160-180 ° C. to 25 ° C. with a cooling rate = 3 ° C./2 min and data collected every 2 minutes.

[Examples 1 to 9]
The resin and polymer were mixed in a 5 gallon metal bucket, and then a premixed slurry of silane and catalyst slurry was added and mixed. This mixture was fed to a 30 mm twin screw extruder at a flow rate of about 10 lbs / hr. The table shows the barrel temperature (bl temp), screw speed (rpm), and vacuum conditions (vacuum mmHg).

  In the twin screw extruder, before each vacuum stage, there are two reversing elements (10/10 counterclockwise) used to create a seal before the vacuum. Under each vacuum port, 3-4 long transport elements (42/42) are used, the material can have more surface area and have a longer residence time to the vacuum.

  When resin B was used, the viscosity of the mixture (resin, polymer, silane, and catalyst) was much lower. Using a flow rate of 10 lbs / hr, significant swell (surging) was observed and the material could not be stripped well. To solve this problem, transport elements with smaller extrusion capabilities (eg using 42/42 and 28/28 instead of 20/20) and one reverse element for the second and third Added during vacuum.

[Example 1]
Example 1 shows the effect of vacuum and rpm on nvc and viscosity.

[Example 2]
Example 2 shows the effect of changing catalyst levels on viscosity at two different resin contents.

[Example 3]
Example 3 shows the effect of crosslinker volatility on nvc and viscosity.

[Example 4]
Example 4 shows that a partially capped polymer can be used to make the hot melt adhesive.

[Example 5]
Example 5 mainly shows the effect of vacuum on nvc. In these cases, Me ₃ capped resin is used. The last three samples are repeats of each other.

[Example 6]
This sample shows the effect of the catalyst on the viscosity and the resin is Me ₃ capped.

[Example 7]
Example 7 shows that other titanate catalysts can be used to make hot melt adhesives.

[Example 8]
Example 8 shows that fillers and adhesion promoters can be used.

[Example 9]
Example 9 shows that useful hot melt materials can be made by oxime curing.

[Example 10]
For these samples, a 50 mm twin screw mixer with L / D = 50 was used. The resin and polymer were premixed in the tank and then transferred to another tank used to feed the mixer (both tanks can be heated and the feed temperature of the resin and polymer mixture is shown below. ); Use three vacuum stages to remove solvent from the process, the three vacuum stages are at 13.93D, 20.86D, and 30.87D; the mixture of crosslinker and catalyst is 35. The final vacuum was applied at 45.86D.

  Example 10 shows that the resin and polymer can be supplied separately from the crosslinker and catalyst to make a hot melt adhesive. Similarly, it shows that the resin and polymer streams can be heated before being introduced into the mixer.

[Example 11]
Resin B (65 pbw (parts by mass)) and polymer A (35 pbw) were mixed for 30 minutes. A slurry pre-mixed with alkoxysilane A (8 pbw) and titanate catalyst A (0.1 pbw) was added to the resin and polymer mixture and stirred for 10 minutes. The resulting mixture was fed through a twin screw extruder under heat and vacuum to produce a hot melt sealant.

  The hot melt sealant was used to make a cured film by preparing a film having a thickness of 0.254 centimeters (cm) and curing at room temperature for 21 days. The cured film was cut into 2.54 × 2.54 cm pieces. Each piece was applied onto a first substrate, and the second substrate was pressed onto the cured film piece to create a cured film laminate.

  The hot melt sealant was heated to 121 ° C. and applied onto the first substrate. A second substrate was pressed over the hot melt, creating a 0.254 cm thickness between the first and second substrates to form a wet film laminate. All laminates were cured at room temperature for at least 21 days.

  Table 11 shows the shear force measured by the Sintech shear test apparatus for each of the laminate number, the substrate used in each laminate, and the cured laminate. In Table 11, G represents glass, A represents aluminum, PC represents polycarbonate, and W represents wood.

Example 11 shows that a hot melt adhesive composition made by the method of the present invention effectively laminates various substrates.
[Comparative Example 1]
Samples are prepared by mixing the ingredients in Table 11A.

  A laminate was prepared using the compositions of Comparative Examples 1 and 11. Lap shear was measured at 0.0847 cm / sec for a laminate having an overlap of 6.45 square cm and a thickness of (adhesive layer) of 0.254 cm. Tensile shear was measured several times when the composition was cured for 14 days. The results are in Table 12.

  The hot melt adhesive compositions and hot melt adhesives prepared by curing the hot melt adhesive compositions have found use in the building and electronics industries. The said hot-melt-adhesive composition and hot-melt-adhesive can be used for the construction industry, for example, the application to a window. The hot melt adhesive composition and the hot melt adhesive can be used in the electronics industry, for example, in lid sealing applications.

FIG. 1 is a portion of a window made in accordance with the present invention. FIG. 2 is a schematic illustration of a housing with a lid seal made in accordance with the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Sash 101 ... Hot-melt-adhesive composition 102 ... Heat insulation glass unit 103 ... Window glass 104 ... Window glass 105 ... Spacer 106 ... Hot-melt-adhesive composition 200 ... Housing 201 ... Hot-melt-adhesive composition 202 ... Container 203 ... Lid 204 ... Electronic components

Claims (16)

The following steps:
(A) In a continuous mixing device,
(1) A silicone resin having a silanol content of less than 2% by mass and containing a monofunctional unit represented by R ¹ ₃ SiO _1/2 and a tetrafunctional unit represented by SiO _4/2 (Where R ¹ is a substituted or unsubstituted monovalent hydrocarbon residue),
(2) an organopolysiloxane containing _a difunctional unit of the formula R ² R ³ SiO and a terminal unit of the formula R ⁴ _a X ′ _3-a SiG— (where R ² is an alkoxy group or a monovalent unsubstituted or R ³ is a monovalent unsubstituted or substituted hydrocarbon residue; R ⁴ is aminoalkyl or R ¹ group, X ′ is a hydrolyzable group; G is a silicon atom of the terminal unit; A divalent group linked to a silicon atom, and a is 0 or 1),
(3) 0.5-15 parts silane crosslinker of silicone resin and organopolysiloxane, and (4) supplying a solvent;
(B) creating the mixture of (1) to (4) in the continuous mixing apparatus;
(C) sufficiently removing volatile components from the mixture in the continuous mixing apparatus until the mixture has a non-volatile component content of at least 97% by weight; and (D) a hot melt adhesive composition. Collecting,
A continuous process for producing a hot melt adhesive composition comprising:   The process according to claim 1, wherein the mixture of (1) to (4) is produced at a temperature of 50 to 250C.   The process of claim 1, wherein the silane crosslinker is added to the mixture after the volatile components are removed.   The process of claim 1, wherein the silane crosslinker and catalyst are added to the mixture after the volatile components are removed.   The process of claim 1, wherein the mixture further comprises at least one (5) adhesion promoter, and (6) a filler.   The process of claim 1, wherein the continuous mixing device is an extruder.   The process of claim 6, wherein the extruder is a twin screw extruder.   The process of claim 1, wherein a vacuum is applied to the continuous mixing device to help remove any volatile components.   The process of claim 1, wherein the hot melt adhesive composition has a viscosity of 200-10000 poise at 120 ° C. The following steps:
(A) applying the film of the hot melt adhesive composition produced by the continuous process according to claim 1 to the surface of the first substrate;
(B) bringing the surface of the second substrate into contact with the film of the hot melt adhesive composition;
(C) pressing the first and second substrates together;
(D) exposing the hot melt adhesive composition to moisture, curing the hot melt adhesive composition and producing a laminate;
A process for manufacturing a laminate comprising: The following steps:
(A) preparing a thin film of the hot melt adhesive composition produced by the continuous process of claim 1;
(B) exposing the film of the hot melt adhesive composition to moisture and curing the hot melt adhesive composition to form a cured film;
(C) applying the cured film to the surface of the first substrate;
(D) contacting the surface of the second substrate with the cured film;
(E) pressing the first and second substrates together to produce a laminate;
A process for manufacturing a laminate comprising:   12. The process according to claim 10 or 11, wherein the first and second substrates are each independently selected from glass, metal, ceramic material, plastic, and cellulosic substrate.   The process of claim 12, wherein the first and second substrates are the same.   A hot melt adhesive composition made by the process of claim 1.   The laminated body manufactured by the process of Claim 10 or 11. Use of a hot melt adhesive composition according to claim 14 in applications in the construction industry or in the electronics industry.

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