WO2025174788A1 - Insert molding and in-mold coating over substrates with pressure sensitive elements - Google Patents

Abstract

Provided is a process for insert molding comprises introducing a film having an element on one side, into which a separate reinforcement piece fits inside. A thermoplastic composition is introduced to the back side of the film at pressures of 5,000 kPa to 15,000 kPa. Then the thermoplastic composition is cooled before the separate reinforcement piece is removed. Provided also is a process for in-mold coating comprises introducing a substrate having an element on one side, into which a separate reinforcement piece fits inside. A coating composition is introduced onto the substrate and the exterior surface of the element, at pressures of 5,000 kPa to 15,000 kPa. Then the thermoplastic composition is cooled before the separate reinforcement piece is removed.

Description

INSERT MOLDING AND IN-MOLD COATING OVER SUBSTRATES WITH PRESSURE SENSITIVE ELEMENTS

FIELD OF THE INVENTION

[0001] The present invention relates to insert molding and in-mold coating of thermoplastics and other polymers, over substrates having pressure sensitive parts.

BACKGROUND OF THE INVENTION

[0002] KR 2004 0101973 discloses an insert type connector molding apparatus made of a positioning jig installed at a lower molding plate, a board jig installed at the lower molding plate, a terminal jig. and a compensation jig. The positioning jig is coupled to a positioning hole formed at a circuit board, and precisely disposes the circuit board on molding spaces. The board jig supports the circuit board with a predetermined pressure so that the surface of an upper connecting terminal adheres closely to the surface of an upper molding plate. The terminal jig is installed at the lower molding plate, and presses the surface of a lower connecting terminal bent downward from the circuit board w ith a predetermined pressure. The compensation jig is installed at the upper molding jig. and presses the rear of the lower connecting terminal with a pressure corresponding to the pressure of the terminal jig. Thus, KR 2004 0101973 discloses a w ay to provide reinforcement, but does so at the expense of costly and complicated tooling which restricts part design flexibility / options.

SUMMARY OF THE INVENTION

[0003] In contradistinction, the inventive approach allows simple tooling without the need for jigs to provide the reinforcement for the female connector resulting in tooling that allow s for increased part design / flexibility with lower overall cost.

[0004] In an embodiment, a process for insert molding comprises (a) introducing a film having a first side and a second side, wherein the first side has an element with an opening attached thereto, into a mold cavity of a mold; (b) inserting a separate reinforcement piece inside of the opening of the element; (c) introducing a thermoplastic composition onto the second side of the film; (d) back molding the film with the thermoplastic composition, w herein the pressure of the thermoplastic composition against the second side of the film is 5,000 to 15,000 kPa, preferably 7,000 to 15.000 kPa; (e) cooling the thermoplastic composition in the mold cavity to at or below 50°C; and (f) removing the separate reinforcement piece from the opening of the element.

[0005] In other embodiments, the film may comprise polyamide or polycarbonate. In others, the element with an opening is at least one of electronic circuits, light emitting diodes and female connectors. The element with an opening may be exposed to a pressure during the back molding step of 5,000 to 15,000 kPa. The element with an opening may be in contact with the first side of the film during back molding. In a preferred embodiment, the element with an opening is a female connector.

[0006] In additional embodiments, the separate reinforcement piece comprises a metal, a structural polymer, wood, rigid foam or rigid elastomers. In preferred embodiments, the separate reinforcement piece comprises or consists of aluminum or is an epoxy.

[0007] In another embodiment, the film has at least two elements with an opening attached thereto, and the separate reinforcement piece is inserted into each opening of the at least two elements.

[0008] In still other embodiments, the thermoplastic composition comprises polycarbonate, and optionally may further comprise a filler selected from the group consisting of glass, graphite, talc and titanium dioxide.

[0009] In yet additional embodiments, the thermoplastic composition may be introduced at a temperature of 260-350°C, preferably 280-330°C. In others, the process further comprises the step of adding a pressure-sensitive adhesive to the second side of the film, before introducing the thermoplastic composition to the film.

[0010] In another embodiment not yet disclosed, a process for in-mold coating comprises (a) introducing a substrate comprising an element attached thereto, the element having an exterior surface and an opening exposing an interior surface, into a mold cavity of a mold; (b) inserting a separate reinforcement piece inside of the opening of the element; (c) introducing a coating composition into the mold cavity containing the substrate: (d) coating the substrate at a processing temperature, and at a processing pressure of 11,000 to 20.700 kPa; (e) curing the coating composition in the mold cavity at cure temperature of 62-105°C; and (I removing the separate reinforcement piece from the opening of the element, wherein the exterior surface of the element is exposed to the coating composition, and wherein the coating composition after curing has a thickness of 0.05 mm to 3.5 mm.

[0011] Optionally, the substrate comprises aromatic polycarbonate. Furthermore, the element with an opening may be at least one of electronic circuits, light emitting diodes and female connectors, preferably the element with an opening is a female connector.

[0012] In other embodiments, the coating composition comprises (i) a polymer comprising isocyanate-reactive groups and (ii) a polyisocyanate. Additionally, the polymer comprising isocyanate-reactive groups may comprise an aromatic branched polyester polyol and an aliphatic polycarbonate polyol. Furthermore, the aliphatic polycarbonate polyol may be a polycarbonate diol, or the polyisocyanate may comprise an isocyanurate of hexamethylene diisocyanate.

[0013] In different embodiments, the coating composition further comprises a plasticizer. In others, the coating composition has a viscosity of 200 to 500 mPa s at the processing temperature. In additional embodiments, the coating composition has a thickness of 0.5 mm - 3.0 mm, or the processing temperature is 50-120°C, preferably 50- 80°C. most preferably 66-77°C. In another, the processing pressure is 12.400 to 15,200 kPa. 32. Additionally, the mold cavity may be at a mold temperature of 71 to 82°C.

BRIEF DESCRIPTION OF THE FIGURES

[0014] FIG. 1 shows a top view of a film comprising electronics and a connector on one side;

[0015] FIG. 2 shows a perspective view of the film of Fig. 1;

[0016] FIG. 3 shows a perspective view of a separate reinforcement piece;

[0017] FIG. 4 shows another perspective view of the separate reinforcement piece of Fig. 3, shown from another side;

[0018] FIG. 5 shows a top view of the film of Fig. 1, with the separate reinforcement piece of Fig. 3 inserted inside of the connector; and

[0019] FIG. 6 shows a perspective view of the film of Fig. 5.

DETAILED DESCRIPTION OF THE INVENTION [0020] Electronic components and devices include many different parts. It is often advantageous to coat, adhere to even bond such parts together. One example of such a part is a film, or a thin substrate, that has electronic components attached to it. The term “film” is used herein to describe such a thin substrate, that may be used to attach electronic components to it, while still being susceptible to transmitting pressures used in coating or bonding processes, from one side to another, in a way that thicker substrates cannot as they tend to absorb and dissipate such pressures, rather than reflect them to the other side of the film.

[0021] Injection molding processes are known in the art, to create molded parts from thermoplastic resins. In such processes, a thermoplastic resin is melted, and injected into a mold, or “shot” into a mold, where the solid part is shaped by the contours of the mold. Higher pressures are usually necessary to inject the molten resin into the mold, and at a speed that is required to fill the mold, in time to prevent premature cooling. In addition, shorter injection times are preferred to increase throughput, or the number of injection moldings a piece of equipment can perform per hour, to minimize the number of injection molding machines needed, and to increase asset utilization.

[0022] Two-component poly urethane forming coating compositions are widely used because of the many advantageous properties they exhibit. These coating compositions generally comprise a liquid binder component and a liquid hardener/crosslinker component. The liquid binder component may comprise an isocyanate-reactive component, such as a polyol, and the liquid crosslinker component may comprise a polyisocyanate. The addition reaction of the polyisocyanate with the isocyanate-reactive component, which can occur at ambient conditions, produces crosslinked polyurethane networks that form coating films. Polyurethane coatings are used in a wide variety, one of which is often referred to as “in-mold” coating.

[0023] In an in-mold coating application, a coating film is molded over the surface of a molded plastic substrate. In an in-mold coating method the molded plastic part is introduced into a cavity of the mold in which the coating film is injected. The mold may also be a multi-cavity metal mold, wherein the molded plastic part is formed in one cavity of the mold, before moving to a second cavity of the mold. Such a process can have advantages over a single cavity in-mold coating process. For example, cycle time is shorter since it is not composed of the sum of the times of the individual process steps and process parameters can be chosen independently for each cavity. [0024] For both injection molding and in-mold coating processes, there may also be a need to mold or coat onto a film that has sensitive components, such as electronic circuits, light emitting diodes, as well as connectors. Of notable concern, are those components that are pressure sensitive and have an opening than may be damaged when exposed to higher pressures. For in-mold coating, the liquid compositions that are added to form effective coatings are typically polymers having high viscosities, which are added at high temperatures and high pressures. These properties and conditions may result in the coating composition moving, or possibly damaging, the electronic circuits, LEDs and connectors. Meanwhile, conditions must also be present to adequately introduce the coating to the mold, and to cure it, so that it may be effective as a coating, throughout the substrate, as well as preventing damage to the sensitive electronics and connectors.

[0025] A problem with both injection molding and in-mold coating processes having such electronics, LEDs or connectors, is that conventional molding and coating processes often involve higher pressures that may move or damage these sensitive components, such that they may not function as intended. As noted above, higher pressures are usually present in commercially viable injection molding processes. While such sensitive elements may avoid higher pressures by having them attached to the substrate after molding or coating, this necessarily adds another assembly step, which may add more time and complexity to the assembly process. Furthermore, attaching electronics to a film before molding or coating, may be easier and more prone to automation.

[0026] As a result, it would be desirable to provide a process for injection molding or in-mold coating utilizing a process that effectively introduces an injection molding or inmold coating composition upon the substrate and sensitive additions, without damaging such electronics or connectors. The present invention was made in view of the foregoing.

[0027] In the disclosure below, a film has two sides, a first side comprises electronics attached to it, and in particular a female connector which by its nature contains an opening large enough to receive another electrical component during its intended use. The second side does not have any pressure sensitive electronics attached to it. While the invention is described as having a female connector, the invention is not so limited. In particular, a film having any pressure sensitive element with an opening may benefit from the present invention. [0028] The film may comprise polyamide or polycarbonate. Such materials may be created to be very thin, which is useful to hold electronics. However, the nature of the material may make it sensitive to pressure that would be applied on the second side of the film, such that during the application of an injection molded plastic or an in-mold coating, the pressure from those processes against the second side of the film may affect any pressure sensitive elements on the first side of the film, such as the female connector described above.

[0029] The reinforcement piece described herein may be made of a metal, such as aluminum, or a structural polymer, such as an epoxy. In other embodiments, the reinforcement piece may be wood, a rigid foam or a rigid elastomer. The reinforcement piece may be a combination of materials and may only comprise one or more of them. In all embodiments, the reinforcement piece is separate from the mold and is not part of the tooling. The separate reinforcement piece fits into the opening of the pressure sensitive element during molding or coating and is then removed after such process. The reinforcement piece may be designed to fit into more than one opening at the same time. In a preferred embodiment, the reinforcement piece comprises a rectangular or square shaped element that fits into a rectangular or square shaped opening such as a female connector, that is sized such that its surfaces, when placed inside of the connector, fill the opening of the connector to prevent the connector itself from buckling or collapsing when exposed to pressure against it.

I. Injection Molding

[0030] In one application of the inventive process, the film with the electronics is placed inside the cavity of a mold. A separate reinforcement piece is placed inside of the opening. A thermoplastic composition is introduced into the cavity, and in particular is back molded against the second side of the film. The pressure against the second side of the film is high, between 5,000 and 15,000 kPa. or 7,000 to 15.000 kPa. Then, the thermoplastic composition is allowed to cool to at or below 50°C, before the separate reinforcement piece is removed from opening. Then, the molded film comprising electronics is removed from the mold. The element with the opening may be exposed to a pressure during the back molding stop of 5,000 to 15,000 kPa. The element with the opening may be in contact with the first side of the film during the back molding process. [0031] Thermoplastic compositions used in association with the present invention may comprise one or more of the following components. The components are then combined into compositions, as they described below. Thermoplastic compositions for reflector materials are described in US Pat. Pub. No. 2014/0356551, which is incorporated by reference. Thermally conductive materials are described in U.S. Pat. Nos. 6,048,919 and 7,235.918; U.S. Pat. App. Pub. Nos. 2005/0272845, 2008/0287585, 2010/0072416 and 2017/0002247; and also published international applications WO 2009/115512, WO 2011/013645 and WO 2017/005735, the disclosures of which are each incorporated by reference herein.

[0032] The process of the present invention utilizes thermoplastic compositions such as ones comprising polycarbonate resins, and optionally copolymers and additives. Suitable polycarbonate resins include homopolycarbonates and copolycarbonates, both linear or branched resins and mixtures thereof.

[0033] Polycarbonates in the context of the present invention are either homopolycarbonates or copolycarbonates and/or polyestercarbonates; the polycarbonates may, in a known manner, be linear or branched. According to the invention, it is also possible to use mixtures of polycarbonates.

[0034] A portion of up to 80 mol%, preferably of 20 mol% up to 50 mol%, of the carbonate groups in the polycarbonates used in accordance with the invention may be replaced by aromatic dicarboxylic ester groups. Polycarbonates of this kind, incorporating both acid radicals from the carbonic acid and acid radicals from aromatic dicarboxylic acids in the molecule chain, are referred to as aromatic polyestercarbonates. In the context of the present invention, they are encompassed by the umbrella term of the thermoplastic aromatic polycarbonates.

[0035] The polycarbonates are prepared in a known manner from bishydroxyaryl compounds, carbonic acid derivatives, optionally chain terminators and optionally branching agents, with preparation of the polyestercarbonates by replacing a portion of the carbonic acid derivatives with aromatic dicarboxylic acids or derivatives of the dicarboxylic acids, according to the carbonate structural units to be replaced in the aromatic polycarbonates by aromatic dicarboxylic ester structural units.

[0036] Dihydroxyaryl compounds suitable for the preparation of polycarbonates are those of the formula (2) HO-Z-OH (2), in which

Z is an aromatic radical which has 6 to 30 carbon atoms and may contain one or more aromatic rings, may be substituted and may contain aliphatic or cycloaliphatic radicals or alkylaryls or heteroatoms as bridging elements.

[0037] Preferably, Z in formula (2) is a radical of the formula (3) in which

R⁶ and R⁷ are each independently H, Ci- to Cis-alkyl-, Ci- to Ci8-alkoxy, halogen such as Cl or Br or in each case optionally substituted ary l or aralkyl, preferably H or Ci- to C -alkyl, more preferably H or Ci- to C's-alkyl and most preferably H or methyl, and

X is a single bond, -SO2-, -CO-, -O-, -S-, Ci- to Ce-alkylene. C2- to C5- alkylidene or C5- to Ce-cycloalkylidene which may be substituted by Ci- to Ce-alkyl, preferably methyl or ethyl, or else Ce- to Ci2-arylene which may optionally be fused to further aromatic rings containing heteroatoms.

Preferably, X is a single bond, Ci- to Cs-alkylene, C2- to Cs-alkylidene, C5- to Ce- cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO2- or a radical of the formula (3a)

[0038] Examples of dihydroxy aryl compounds (diphenols) are: dihydroxybenzenes, dihydroxy diphenyls, bis(hydroxyphenyl)alkanes, bis(hydroxyphenyl)cycloalkanes, bis(hydroxyphenyl)aryls, bis(hydroxyphenyl) ethers, bis(hydroxyphenyl) ketones, bis(hydroxyphenyl) sulphides, bis(hydroxyphenyl) sulphones, bis(hydroxyphenyl) sulphoxides, l.l’-bis(hydroxyphenyl)diisopropylbenzenes and the ring-alkylated and ring-halogenated compounds thereof.

[0039] Examples of bishy droxyarvl compounds suitable for the preparation of the polycarbonates for use in accordance with the invention include hydroquinone, resorcinol, dihydroxy diphenyl, bis(hydroxyphenyl)alkanes, bis(hydroxyphenyl)cycloalkanes, bis(hydroxyphenyl) sulphides, bis(hydroxyphenyl) ethers. bis(hydroxyphenyl) ketones, bis(hydroxyphenyl) sulphones, bis(hydroxyphenyl) sulphoxides, a.a'- bis(hydroxyphenyl)diiso-propylbenzenes and the alkylated, ring-alkylated and ring- halogenated compounds thereof.

[0040] Preferred bishydroxyaryl compounds are 4,4’-dihydroxydiphenyl, 2,2-bis(4- hy droxyphenyl)- 1 -phenylpropane, 1 , 1 -bis(4-hydroxyphenyl)phenylethane, 2,2-bis(4- hydroxyphenyl)propane, 2, 4-bis(4-hydroxyphenyl)-2 -methylbutane, 1 ,3 -bis [2-(4- hydroxyphenyl)-2-propyl]benzene (bisphenol M), 2,2-bis(3-methyl-4- hydroxyphenyl)propane, bis(3,5-dimethyl-4-hydroxyphenyl)methane, 2,2-bis(3,5- dimethyl-4-hydroxyphenyl)propane, bis(3,5-dimethyl-4-hydroxyphenyl) sulphone, 2,4- bis(3.5-dimethyl-4-hydroxyphenyl)-2 -methylbutane, l,3-bis[2-(3.5-dimethyl-4- hydroxyphenyl)-2-propyl]benzene and l,l-bis(4-hydroxyphenyl)-3.3.5- trimethylcyclohexane (bisphenol TMC).

[0041] Additional preferred bishydroxylaryl compounds include at least one monomer unit derived from a bis-(4-hy droxyphenyl) compound, which is bridged via the l.l'-position of a cyclic hydrocarbon optionally substituted by heteroatoms, preferably one via the 1.1'- (la), (lb), (1c) and (Id), more preferably a monomer unit bridged over the l.l'-position of a cyclic hydrocarbon, which is described by the general formula (la):

(1 c) (1d) in which:

R¹ is hydrogen or Cl-C4-alkyl, preferably hydrogen,

R² is Cl-C4-alkyl, preferably methyl,

N is 0, 1, 2 or 3, preferably 3, and

R³ is Cl-C4-alkyl, aralky l or aryl, preferably methyl or phenyl, very particularly preferably phenyl.

[0042] Particularly preferred bishydroxyaryl compounds are 4,4’-dihydroxydiphenyl, l,l-bis(4-hydroxyphenyl)phenylethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3,5- dimethyl-4-hydroxyphenyl)propane, l,l-bis(4-hydroxyphenyl)cyclohexane and 1, 1 -bis(4- hydroxyphenyl)-3,3,5-trimethylcyclohexane (bisphenol TMC).

[0043] These and further suitable bishydroxyaryl compounds are described, for example, in US 2 999 835 A, 3 148 172 A, 2 991 273 A, 3 271 367 A, 4 982 014 A and 2 999 846 A, in German published specifications 1 570 703 A, 2 063 050 A, 2 036 052 A, 2 211 956 A and 3 832 396 A, in French patent 1 561 518 Al, in the monograph "H. Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, New York 1964, p. 28 ff ; p.102 ff.", and in "D.G. Legrand, J.T. Bendler, Handbook of Polycarbonate Science and Technology, Marcel Dekker New York 2000. p. 72ff."

[0044] Only one bishydroxy aryl compound is used in the case of the homopolycarbonates; two or more bishydroxyaryl compounds are used in the case of copolycarbonates. The bishydroxyaryl compounds employed, similarly to all other chemicals and assistants added to the synthesis, may be contaminated with the contaminants from their own synthesis, handling and storage. However, it is desirable to employ the purest possible raw materials.

[0045] The monofunctional chain terminators needed to regulate the molecular weight, such as phenols or alkylphenols, especially phenol, p-tert-butylphenol, isooctylphenol, cumylphenol, the chlorocarbonic esters thereof or acid chlorides of monocarboxylic acids or mixtures of these chain terminators, are either supplied to the reaction together with the bisphenoxide(s) or else added to the synthesis at any time, provided that phosgene or chlorocarbonic acid end groups are still present in the reaction mixture, or, in the case of the acid chlorides and chlorocarbonic esters as chain terminators, provided that sufficient phenolic end groups of the polymer being formed are available. Preferably, the chain terminator(s), however, is/are added after the phosgenation at a site or at a time when no phosgene is present any longer but the catalyst has still not been metered in, or are metered in prior to the catalyst, together with the catalyst or in parallel.

[0046] Any branching agents or branching agent mixtures to be used are added to the synthesis in the same manner, but typically before the chain terminators. Typically, trisphenols, quaterphenols or acid chlorides of tri- or tetracarboxylic acids are used, or else mixtures of the polyphenols or of the acid chlorides.

[0047] Some of the compounds having three or more than three phenolic hydroxyl groups that are usable as branching agents are, for example, phloroglucinol, 4,6-dimethyl- 2,4,6-tri(4-hydroxyphenyl)hept-2-ene, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)heptane, 1 ,3,5-tris(4-hydroxyphenyl)benzene, 1,1,1 -tri-(4-hydroxyphenyl)ethane, tris(4- hydroxyphenyl)phenylmethane, 2,2-bis[4,4-bis(4-hydroxyphenyl)cyclohexyl]propane, 2,4-bis(4-hydroxyphenylisopropyl)phenol, tetra(4-hydroxyphenyl)methane. [0048] Some of the other trifunctional compounds are 2,4-dihydroxybenzoic acid, trimesic acid, cyanuric chloride and 3.3-bis(3-methyl-4-hydroxyphenyl)-2-oxo-2,3- dihydroindole.

[0049] Preferred branching agents are 3.3-bis(3-methyl-4-hydroxyphenyl)-2-oxo-2,3- dihydroindole and l,l,l-tri(4-hydroxyphenyl)ethane.

[0050] The amount of any branching agents to be used is 0.05 mol% to 2 mol%, again based on moles of bishy droxyaryl compounds used in each case.

[0051] The branching agents can either be initially charged together with the bishy droxyaryl compounds and the chain terminators in the aqueous alkaline phase or added dissolved in an organic solvent prior to the phosgenation.

[0052] All these measures for preparation of the polycarbonates are familiar to those skilled in the art.

[0053] Aromatic dicarboxylic acids suitable for the preparation of the polyestercarbonates are, for example, orthophthalic acid, terephthalic acid, isophthalic acid, tert-butylisophthahc acid, 3,3'-diphenyldicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4-benzophenonedicarboxylic acid, 3,4'-benzophenonedicarboxylic acid, 4, d'diphenyl ether dicarboxylic acid, 4,4'-diphenyl sulphone dicarboxylic acid, 2,2-bis(4- carboxyphenyl)propane, trimethyl-3-phenylindane-4,5'-dicarboxylic acid.

[0054] Among the aromatic dicarboxylic acids, particular preference is given to using terephthalic acid and/or isophthalic acid.

[0055] Derivatives of the dicarboxylic acids are the dicarbonyl dihalides and the dialkyl dicarboxylates, especially the di carbonyl dichlorides and the dimethyl dicarboxylates.

[0056] The replacement of the carbonate groups by the aromatic dicarboxylic ester groups proceeds essentially stoichiometrically and also quantitatively, and so the molar ratio of the co-reactants is reflected in the final polyester carbonate. The aromatic dicarboxylic ester groups can be incorporated either randomly or in blocks.

[0057] Preferred modes of preparation of the polycarbonates for use in accordance with the invention, including the polyestercarbonates, are the known interfacial process and the known melt transesterification process (cf. e.g. WO 2004/063249 Al, WO 2001/05866 Al, WO 2000/105867, US 5,340,905 A, US 5,097,002 A, US 5.717,057 A).

[0058] In the first case, the acid derivatives used are preferably phosgene and optionally dicarbonyl dichlorides; in the latter case, they are preferably diphenyl carbonate and optionally dicarboxylic diesters. Catalysts, solvents, workup, reaction conditions etc. for the polycarbonate preparation or polyestercarbonate preparation have been described and are known to a sufficient degree in both cases.

[0059] The technique employed to determine the molecular weight of polycarbonate is gel-permeation chromatography (GPC) using polystyrene calibration standards. A WATERS ALLIANCE 2695 GPC with refractive index (RI) detection is employed for these analyses. The GPC is controlled, data collected, and data analyzed by WATERS EMPOWER chromatography software. The columns employed include three 30 cm SDVB PL Gel Mixed E columns with a 5 pm 2-Mixed D guard column. The mobile phase is tetrahydrofuran (THF). Toluene is used for elution-time correction. The flow rate is 1.0 mL/min. at 35 °C, with a run-time of 40 min. Polystyrene calibration standards are used as primary calibrators and CD-2000, 2450 and 3400 are employed as secondary standards. The sample injection volume is 75 pL with a sample concentration of 2.5 mg/mL.

[0060] The thermoplastic composition may also include a copolymer, along with additional vinyl monomers such as vinyl aromatic compounds and/or vinyl aromatic compounds substituted on the ring (such as styrene, a-methyl styrene, p-methyl styrene, p- chlorostyrene), methacrylic acid (Ci-Cs)-alkyl esters (such as methyl methacrylate, ethyl methacrylate. 2-ethylhexyl methacrylate, allyl methacrylate), acrylic acid (Ci-Cs)-alkyl esters (such as methyl acrylate, ethyl acrylate, n-butyl acrylate, tert-butyl acrylate), polybutadienes, butadiene/styrene or butadiene/acrylonitrile copolymers, polyisobutenes or polyisoprenes grafted with alkyl acrylates or methacrylates, vinyl acetate, acry lonitrile and/or other alkyl styrenes, organic acids (such as acry lic acid, methacry lic acid) and/or vinyl cyanides (such as acrylonitrile and methacrylonitrile) and/or derivatives (such as anhydrides and imides) of unsaturated carboxylic acids (for example maleic anhydride and N-phenyl-maleimide). These vinyl monomers can be used on their own or in mixtures of at least two monomers. Preferred monomers in the copolymer can be selected from at least one of the monomers styrene, methyl methacry late, n-butyl acrylate and acrylonitrile butadiene styrene. [0061] The thermoplastic composition may optionally comprise one or more further commercially available polymer additives such as flame retardants, flame retardant synergists, anti-dripping agents (for example compounds of the substance classes of the fluorinated polyolefins, of the silicones as well as aramid fibers), lubricants and mold release agents (for example pentaerythritol tetrastearate), nucleating agents, stabilizers, antistatic agents (for example conductive blacks, carbon fibers, carbon nanotubes as well as organic antistatic agents such as polyalkylene ethers, alkylsulfonates or polyamide- containing polymers), as well as colorants and pigments.

[0062] In particular, the thermoplastic composition may contain a filler selected from the group consisting of glass, graphite, talc and titanium dioxide.

[0063] In some compositions, a thermally conductive additive may be included. Such an additive may be graphene, graphite, aluminum or other metal particles, carbon fiber, or other conductor, or thermally conductive polymers. In a preferred embodiment, expanded graphite is the thermally conductive additive.

[0064] Expanded graphite and methods of its production are known to those skilled in the art. Expanded graphite useful is present in an amount ranging from 10% to 70% of the composition of the present invention, more preferably from 20% to 60% and most preferably from 30% to 50%. The expanded graphite may be present in the composition of the present invention in an amount ranging between any combination of these values, inclusive of the recited values. The present inventors have found that at least 90% of the particles of the expanded graphite should have a particle size of at least 200 microns.

[0065] The preparation of polymer compositions that may be used according to the invention is carried out with the usual processes of incorporation by bringing together, mixing and homogenizing the individual constituents, the homogenizing in particular preferably taking place in the melt under the action of shearing forces. The bringing together and mixing are optionally carried out before the melt homogenization, using powder premixes.

[0066] Premixes of granules or granules and powders with the additives according to the invention can also be used. Premixes which have been prepared from solutions of the mixing components in suitable solvents, homogenization optionally being carried out in solution and the solvent then being removed, can also be used. [0067] In particular, the additives of the composition according to the invention can be introduced here by known processes or as a masterbatch. The use of masterbatches is preferred in particular for introduction of the additives, masterbatches based on the particular polymer matrix being used in particular.

[0068] In this connection, the composition can be brought together, mixed, homogenized and then extruded in conventional devices, such as screw extruders (for example twin-screw extruders, TSE), kneaders or BRABENDER or BANBURY mills. After the extrusion, the extrudate can be cooled and comminuted. Individual components can also be premixed and the remaining starting substances can then be added individually and/or likewise as a mixture.

[0069] The bringing together and thorough mixing of a premix in the melt can also be carried out in the plasticizing unit of an injection molding machine. In this procedure, the melt is converted directly into a shaped article in the subsequent step.

[0070] An embodiment of the inventive process has the following order: First, the film with the electronics is placed inside the cavity of a mold. Second, the separate reinforcement piece is placed inside of the opening. Third, a thermoplastic composition is introduced into the cavity, and in particular is back molded against the second side of the film. The pressure against the second side of the film is high, betw een 5,000 and 15,000 kPa, or 7.000 to 15,000 kPa. Fourth, the thermoplastic composition is allowed to cool to at or below 50°C. Fifth, the separate reinforcement piece is removed from opening. Sixth, the molded film comprising electronics is removed from the mold. In an embodiment, a pressure-sensitive adhesive is added to the second side of the film, before introducing the thermoplastic composition to the film.

[0071] The process of dynamic mold temperature control in injection molding is characterized in that the mold wall is heated up s iftly before injection of the melt. Due to the elevated mold temperature, premature solidification of the melt is prevented, so that inter alia a higher casting accuracy of the mold surface is possible and the quality of the component surface improves. The temperature of the mold wall should be in the region of the Vicat temperature of the composition that is being molded +/- 40 °C, preferably in the region +/- 20 °C. The Vicat temperature is measured by ASTM D-1525. Dynamic mold temperature control is furthermore characterized in that the temperature of the mold wall after the injection operation may be controlled, to prevent cooling before and during the second shot injection, and then to allow cooling to the original temperature, and the finished component is cooled down to the mold release temperature in the mold in the conventional manner. For the examples mentioned in the following, dynamic mold temperature control with the aid of induction heating was used.

[0072] In an embodiment, the injection temperature of the thermoplastic composition is from 260°C to 350°C, preferably 280°C to 330°C.

[0073] The injection speed is preferably high to ensure a short dwell time of the material being injected. In another preferred embodiment, injection speeds of 25 mm/ sec to 200 mm/ sec are preferred to minimize the cooling of the material, as well as to prevent any buildup of pressure in the cavity.

II. In-Mold Coating

[0074] In an embodiment, a process for in-mold coating comprises first introducing a substrate having an element with an opening attached thereto, into a mold cavity of a mold. Second, a separate reinforcement piece is inserted inside of the opening of the element. Third, a coating composition is introduced into the mold cavity containing the substrate. Fourth, the substrate, and the exterior surface of the element with the opening, is coated at a processing pressure of 11,000 to 20,700 kPa. Fifth, the coating composition is cured in the mold cavity at cure temperature of 62-105°C. Sixth, the separate reinforcement piece is removed from the opening of the element. In contrast to the injection molding process described above, the side of the substrate having the element is coated in the process.

[0075] A substrate having additional components is introduced into a mold. The separate reinforcement piece may be added before or after the substrate is introduced to the mold. This mold may optionally be a second cavity of the same mold that was used to mold the substrate, or to apply the additional components. The mold is opened and the substrate is transferred into a cavity. The transfer of the substrate may be carried out by any of a variety of methods. Specific examples of suitable methods include, but are not limited to, transfer with a rotary table, turning plate, sliding cavity and index plate as well as comparable methods in which the substrate remains on the core. If the substrate remains on the core for the transfer, this has the advantage that the position is also accurately defined after the transfer. On the other hand, methods for transfer of a substrate in which the substrate is removed from one cavity, e.g. with the aid of a handling system, and laid into another cavity are also suitable.

[0076] According to embodiments of the processes of the present invention, a coating composition is introduced into the mold cavity containing the molded plastic substrate and separate reinforcement piece in order to coat the substrate, and any additional components that may be attached thereto. The coating compositions utilized in the processes of the present invention comprise: (i) a polymer comprising isocyanate-reactive groups; and (ii) a polyisocyanate. In certain embodiments, the coating composition is a high solids compositions, which, as used herein, means that the coating composition comprises no more than 10 wt.%, preferably not more than 2 wt.%, in particular not more than 1 wt.% of volatile materials (such as organic solvents or water) based on the total weight of the composition. In certain embodiments, the composition is a 100% solids composition that has a relatively low viscosity, which, as used herein means a viscosity at 23°C of no more than 12,000 mPa s, when measured according to DIN EN ISO 3219/ A3 determined using a rotational viscometer - VISCO TESTER 550, Thermo Haake GmbH), hydroxyl content of 15.4-16.6% (measured according to DIN 53 240/2.

[0077] Suitable polymers comprising isocyanate-reactive groups include, for example, polymeric polyols, such as, for example, polyether polyols, polyester polyols, and/or polycarbonate polyols, among others.

[0078] Suitable polyether polyols, include, without limitation, those having a Mn of 100 to 4,000 g/mol. Polyether polyols which are formed from recurring ethylene oxide and propylene oxide units are sometimes used, such as those having a content of from 35 to 100% of propylene oxide units, such as 50 to 100% of propylene oxide units. These can be random copolymers, gradient copolymers or alternating or block copolymers of ethylene oxide and propylene oxide. Suitable polyether polyols derived from recurring propylene oxide and/or ethylene oxide units are commercially available and include, for example, those available from, for example, Covestro LLC, Pittsburgh, Pennsy lvania (such as e.g. DESMOPHEN 3600Z, DESMOPHEN 1900U, ACCLAIM Polyol 2200, ACCLAIM Polyol 40001, ARCOL Polyol 1004, ARCOL Polyol 1010. ARCOL Polyol 1030, ARCOL Polyol 1070, BAYCOLL BD 1110, BAYFILL VPPU 0789, BAYGAL K55, PET® 1004, POLYETHER SI 80). [0079] In certain embodiments, the polymeric polyol comprises a polyester polyol, such as those having a Mn of 200 to 4.500 g/mol. In certain embodiments, the polyester polyol has a viscosity at 23°C of 700 to 50,000 mPa- s and a hydroxyl number of 200 to 800 mg KOH/g. In certain embodiments, the polyester polyol is based on an aromatic carboxylic polyester with an average hydroxyl functionality of greater than 2, preferably 3 or more, and an average hydroxyl number of 350 to 700 mg KOH/g, such as 450 to 600 mg/KOH/g and a viscosity at 23°C of 1000 to 30000 mPa s. Suitable polyester polyols can be prepared, as will be appreciated, by reacting polyhydric alcohols with stoichiometric amounts of polybasic carboxylic acids, carboxylic anhydrides, lactones or poly carboxylic acid esters of C1-C4 alcohols.

[0080] In certain embodiments, the polyester polyol is derived from one or more of aromatic polybasic carboxylic acids or their anhydride, ester derivatives, e-caprolactone, optionally in a mixture with one or more aliphatic or cycloaliphatic polybasic carboxylic acids or their derivatives.

[0081] Suitable compounds having a number average molecular weight from 1 18 to 300 g/mol and an average carboxyl functionality > 2, which are suitable for use in preparing the polyester polyol, include, but are not limited adipic acid, phthalic anhydride, and isophthalic acid, or a mixture thereof is used.

[0082] For the preparation of the polyester polyols, suitable polyhydric alcohols, in some embodiments, those having a number average molecular weight of 62-400 g/mol, such as 1 ,2-ethanediol, 1 ,2 and 1,3-propanediol, the isomeric butanediols, pentanediols, hexanediols, heptanediols, and octanediols, 1,2, and 1,4-cyclohexanediol, 1,4- cyclohexanedimethanol, 4,4 '- (l-methylethylidene)-biscyclohexanol, 1,2,3-propanetriol, 1,1.1 -trimethylol ethane, 1,2,6-hexanetriol. 1,1,1 -trimethylolpropane, 2,2 (bis(hydroxymethyl)-l,3-propanediol. In certain embodiments, the polyhydric alcohol comprises 1,2-propanediol, 1,3-butanediol, 1,6-hexanediol, neopentyl glycol and/or trimethylolpropane, such as 1,3-butanediol, neopenty l glycol and/or trimethylolpropane. In certain embodiments, the polyester polyol comprises a branched polyester polyol, an example of which is DESMOPHEN XP 2488. available from Covestro LLC. Pittsburgh. Pennsylvania.

[0083] In certain embodiments of the present invention, the polymeric polyol comprises an aliphatic polycarbonate polyol, such as a polycarbonate diol, such as those having a Mn of 200 to 5000 g/mol, such as 150 to 4,500 g/mol, 300 to 2000 g/mol, 300 to 2,500 g/mol or 400 to 1000 g/mol. and a hydroxyl functionality of 1.5 to 5, such as 1.7 to 3 or 1.9 to 2.5. Such polycarbonate polyols can, in certain embodiments, also have a viscosity at 23°C of 2000 to 30,000 mPa s, preferably 2500 to 16000 rnPa s, most preferably 3000 to 5000 mPa s, when measured according to DIN EN ISO 3219/ A3 determined using a rotational viscometer - VISCO TESTER 550, Thermo Haake GmbH, a hydroxyl content of 15.4-16.6% (measured according to DIN 53 240/2), and/or a hydroxyl number of 40 to 300 mg KOH/gram, such as 50 to 200 mg KOH/gram or 100 to 200 mg KOH/gram, when measured by end-group analysis as is well understood in the art.

[0084] Such aliphatic poly carbonate polyols can be prepared, for example, by tranesterification of monomeric dialkyl carbonates, such as dimethyl carbonate, diethyl carbonate or diphenyl carbonate with polyols having a hydroxyl functionality of at least 2.0, such as, for example, 1 ,4-butanediol, 1,3 -butanediol, 1,5-pentandeiol, 1,6-hexanediol, 3 -methyl- 1 ,5 -pentanediol, 1 , 12-dodecanediol, cy clohexanediomethy lol, trimethylolpropane, and/or mixtures of any of these with lactones, such as c-caprolactone. In certain embodiments of the present invention, the aliphatic polycarbonate polyol is prepared from 1,4-butanediol, 1 ,6-hexanediol, 3-methyl-l,5-pentanediol, or a mixture of two or more thereof with s-caprolactone. For example, the DESMOPHEN C types from Covestro LLC, Pittsburgh, Pennsylvania, such as, for example, DESMOPHEN C 1100 or DESMOPHEN C 2200, can be used as polycarbonate diols.

[0085] In certain embodiments of the present invention, the polymer comprising isocyanate-reactive groups comprises (i) a polyester polyol, such as a branched polyester polyol, and (ii) a polycarbonate polyol, such as a polycarbonate diol, such as a polycarbonate polyester diol, such as those based on 1,6-hexanediol and c-caprolactone. In certain embodiments, the weight ratio of (i) and (ii) in the coating compositions used in the processes of the present invention is in the range of 1: 10 to 10: 1, such as 1:5 to 5: 1, 1 :4 to 4: 1, 1:3 to 3: 1, 1 :2 to 2: 1, or, in some cases, it is 1: 1. In certain embodiments, the polymer comprising isocyanate-reactive groups (or mixture of two or more such polymers as described above) is selected so as to have a relatively low viscosity at 23°C (measured according to DIN EN ISO 3219/A.3), preferably no more than 10,000 mPa s. most preferably no more than 8.000 mPa s. [0086] As indicated, the coating compositions used in the process of the present invention further comprise a polyisocyanate. Suitable polyisocyanates include aromatic, araliphatic, aliphatic or cycloaliphatic di- and/or polyisocyanates and mixtures thereof. In certain embodiments, the polyisocyanate comprises a diisocyanates of the formula R(NCO)2, wherein R represents an aliphatic hydrocarbon residue having 4 to 12 carbon atoms, a cycloaliphatic hydrocarbon residue having 6 to 15 carbon atoms, an aromatic hydrocarbon residue having 6 to 15 carbon atoms or an araliphatic hydrocarbon residue having 7 to 15 carbon atoms. Specific examples of suitable diisocyanates include xylylene diisocyanate, tetramethylene diisocyanate, 1,4-diisocyantobutane, 1,12- diisocyanatododecane, hexamethylene diisocyanate, 2,3,3-trimethylhexamethylene diisocyanate. 1,4-cyclohexylene diisocyanate. 4,4'-dicyclohexylmethane diisocyanate, 4,4'-dicyclohexyl diisocyanate, l-diisocyanato-3,3,5-trimethyl-5- isocyanatomethylcyclohexane- (isophorone diisocyanate), 1 ,4-phenylene diisocyanate, 2.6-tolylene diisocyanate, 2,4-tolylene diisocyanate, 1,5-naphthylene diisocyanate, 2.4'- or 4,4'-diphenylmethane diisocyanate, 4.4'-diphenyldimethylmethane diisocyanate. a,a,a',a'-tetramethyl-m- or -p-xylylene diisocyanate, and triphenylmethane 4,4', 4"- triisocyanate as well as mixtures thereof. Also suitable are monomeric triisocyanates such as 4-isocyanatomethyl-l,8-octamethylene diisocyanate.

[0087] Polyisocyanate adducts containing isocyanurate, iminooxadiazine dione, urethane, biuret, allophanate, uretidione and/or carbodiimide groups are also suitable for use in the coating compositions used in the processes of the present invention. Such polyisocyanates may have isocyanate functionalities of 3 or more and can be prepared, for example, by the trimerization or oligomerization of diisocyanates or by the reaction of diisocyanates with polyfunctional compounds containing hydroxyl or amine groups. In one particular embodiment, the poly isocyanate is the isocyanurate of hexamethylene diisocyanate, which may be prepared in accordance with U.S. Pat. No. 4.324.879 at col. 3, line 5 to col. 6, line 47, the cited portion of which being incorporated herein by reference.

[0088] In certain embodiments of the present invention, the coating composition comprises a low viscosity' polyisocyanate having a viscosity at 23°C and at 100% solids of less than 2000 mPa s, such as less than 1500 mPa s or, in some cases, 800 to 1400 mPa s, when measured according to DIN EN ISO 3219/ A3 determined using a rotational viscometer - VISCO TESTER 550, Thermo Haake GmbH; an isocyanate group content of 8.0 to 27.0 wt. %, such as 14.0-24.0 wt. % or 22.5-23.5% (according to DIN EN ISO 11909); an NCO calculated functionality’ of 2.0 to 6.0, such as 2.3 to 5.0 or 2.8 to 3.2; and a content of monomeric diisocyanate of less than 1 wt. %, such as less than 0.5 wt %.

[0089] Examples of these polyisocyanates include isocyanurate group-containing polyisocyanates prepared by trimerizing hexamethylene diisocyanate until the reaction mixture has an NCO content of 42 to 45, such as 42.5 to 44.5 wt. %, subsequently terminating the reaction and removing unreacted hexamethylene diisocyanate by distillation to a residual content of less than 0.5 wt. %; uretdione group-containing polyisocyanates which may present in admixture with isocyanurate group-containing polyisocyanates; biuret group-containing polyisocyanates which may be prepared according to the processes disclosed in U.S. Pat. Nos. 3,124,605; 3,358,010; 3,903,126; and 3,903,127; isocyanurate and allophanate group-containing polyisocyanates which may be prepared in accordance with the processes set forth in U.S. Pat. Nos. 5,124,427, 5,208,334 and 5,235,018; and iminooxadi azine dione and optionally isocyanurate group- containing poly isocyanates which may be prepared in the presence of special fluorine- containing catalysts as described in DE-A 19611849.

[0090] Cyclic and/or linear polyisocyanate molecules may usefully be employed. For improved weathering and diminished yellowing the polyisocyanate(s) of the isocyanate component is typically aliphatic.

[0091] In certain embodiments of the present invention, the polyisocyanate comprises, or, in some cases, consists essentially of, or consist of, a polyisocyanate containing biuret groups, such as the biuret adduct of hexamethylene diisocyanate (HDI) available from Covestro LLC under the trade designation DESMODUR N-100, a polyisocyanate containing isocyanurate groups, such as that available from Covestro LLC under trade designation DESMODUR N-3300, and/or a polyisocyanate containing urethane groups, uretdione groups, carbodiimide groups, allophonate groups, and the like. These derivatives are preferred as they are polymeric, exhibit very' low vapor pressures and are substantially free of isocyanate monomer.

[0092] The pre-reaction of the polyisocyanate with hydroxy group-containing material results in the modified polyisocyanate having a higher molecular weight and lower isocyanate content than the polyisocyanate alone. This will often lead to a higher viscosity in the modified polyisocyanate. It is often desirable that the modified polyisocyanate is low in viscosity, such as those in which the Brookfield viscosity is less than about 10,000 mPa s, such as less than 5,000 mPa s, or. in some cases, less than 4,000 mPa s at temperatures ranging from 25°C to 70°C. Exemplary such polyisocyanates include those commercially available from Covestro LLC under the tradename DESMODUR N-3600, which has a viscosity of 800-1400 mPa- s at 25°C.

[0093] In forming the coating composition used in the process of the present invention, the polymer(s) comprising isocyanate-reactive groups, such as the polyol(s) mentioned earlier and the polyisocyanate(s) are combined in relative amount such that the coating composition has a ratio of isocyanate groups to isocyanate-reactive groups of 0.8 to 3.0: 1, such as 0.8 to 2.0:1, or, in some cases, 1 : 1 to 1.8:1 or 1 : 1 to 1.5: 1. In some embodiments, this ratio is greater than 1:2: 1, such as at least 1:3: 1 and/or up to 1:4: 1. Indeed, it is currently believed that such “over-indexing” of isocyanate groups to isocyanate-reactive groups can be a significant contributor to the ability of a coated molded substrate to de-mold from the second mold cavity via gravity alone or with suction alone after the coating composition has cured, since, under the elevated temperature and elevated pressure cure conditions used in the processes of the present invention all. or substantially all, of the isocyanate-reactive groups, such as hydroxyl groups, are thought to either cure by exposure to moisture or form allophonate groups, thereby providing a more complete cure of the coating composition.

[0094] The coating compositions used in the process of the present invention further comprise a catalyst for the reaction between the isocyanate-reactive group, such as the hydroxyl group, and the isocyanate group. Suitable such catalysts include metallic and nonmetallic catalysts, specific examples of which include, but are not limited to, amine catalysts, such as l,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1 ,4- diazabicyclo[2.2.2]octane (DABCO) or triethanolamine, and Lewis acid compounds, such as dibutyltin dilaurate, lead octoate, tin octoate, titanium and zirconium complexes, cadmium compounds, bismuth compounds, such as bismuth neodecanoate and iron compounds. In certain embodiments, the catalyst is present in the coating composition in an amount of no more than 1.0 wt. %, based on the total solids contents of the composition.

[0095] The coating compositions used in the process of the present invention may further comprise a plasticizer, used to lower the viscosity of the composition. As explained in detail below, the coating composition preferably has a viscosity at processing temperature of 200 - 500 mPa s (200 - 500 centipoise), and the processing temperature is 50-120°C (120-248°F). preferably 50-80°C (120-177°F), most preferably 66-77°C (150-170°F). To achieve this relatively low viscosity level, it may be necessary to add a plasticizer which has been found to lower the viscosity of the composition. The plasticizer is preferably phthalate-free, such as alkyl sulfonic acid ester with phenol, sold under the trademark MESAMOLL by LANXESS Deutschland GmbH, Leverkusen, Germany.

[0096] The coating compositions of the present invention may comprise a silicone, which can act as an internal mold release agent in the coating composition, thereby facilitating the release of the cured coating from a mold cavity by force of gravity alone or with suction alone when the mold is opened. The silicone may be a polyether- modified silicone compound, as such compounds tend to increase the likelihood that the coated molded substrate will release from a mold cavity by the force of gravity alone or with suction alone when the mold is opened.

[0097] Examples of polyether-modified silicones suitable for use in the present invention include compounds in which a poly ether chain is included at ends and/or side chains of a polysiloxane, and also includes a co-modified silicon compound in which a different organic group is also included into polysiloxane. It is also possible that the polyether-modified silicone includes a (meth)acryloyl group in a molecule.

[0098] Examples of polyether-modified silicone compounds, which are suitable for use in the present invention include, but are not limited to, BYK silicones, such as, but not limited to BYK-377, which is a solvent-free polyether-modified, hydroxyl-functional poly dimethylsiloxane, from BYK USA Inc.

[0099] Examples of other internal mold release agents, which are suitable for use in the present invention, include polyester-modified silicone compounds in which a polyester chain is included at ends and/or side chains of a polysiloxane. and also includes a co-modified silicon compound in which a different organic group is also included together into polysiloxane. It is also possible that the polyester modified silicone includes a (meth)acryloyl group in a molecule.

[0100] Examples of polyester-modified silicone compounds, which are suitable for use in the present invention, include, but are not limited to, BYK silicones, such as, but not limited to BYK-370. which is a solution of a polyester-modified, hydroxyl-functional polydimethylsiloxane, 75% solids content in xylene, alkylbenzenes, cyclohexanone, and monophenyl glycol, from BYK USA Inc.

[0101] In certain embodiments of the coating composition used in the processes of the present invention, the internal mold release agent, such as the foregoing silicones, are present in the composition in an amount of 0. 1 to 5 % by weight, such as 0. 1 to 1.0 percent by weight, based on the total weight of the coating composition. In certain embodiments of the present invention, the internal mold release agent is present in the composition in an amount sufficient to provide a cured coating with a surface tension of no more than 30 dynes/cm, such as no more than 25 dynes/cm when measured using a Rame-Hart goniometer in which total solid surface energies, including the polar and dispersive components are calculated using the advancing angles according to the Owens Wendt procedure and in which samples are stacked together without surface protection and the surfaces are lightly brushed to remove dust prior to analysis.

[0102] The coating compositions used in the processes of the present invention may comprise any customary auxiliaries and additives of paint technology, such as defoamers, thickeners, pigments, dispersing assistants, catalysts, anti-skinning agents, anti-settling agents or emulsifiers, for example.

[0103] As previously indicated, in the processes of the present invention, the coating composition is introduced into a mold cavity containing the molded plastic substrate in order to coat the substrate, and the composition is cured in the mold cavity at cure conditions of an elevated pressure and temperature. If two-component coating compositions are employed, particularly those with a short pot life due to the presence of a sufficient amount of cure catalyst, these components may be mixed thoroughly either in an injection nozzle, such as a high pressure counter-current mixing head, or in the feed line by a static mixer or active mixing with the aid of a dynamic mixer, depending on the pot life and installation technology. If the pot life is long due, for example, to the absence of any cure catalyst or a sufficiently low amount of cure catalyst, mixing of the two components may also be carried out outside the installation and the mixture can be processed like a one-component system. In this case, for example, the processing time may be prolonged by cooling the components before injection, and a short reaction time may be achieved by increasing the mold temperature in the cavity'. [0104] In embodiments of the present invention, the coating step is carried out under pressure. This means that the application of the coating composition to the molded plastic substrate is carried out under pressure. In certain embodiments, the coating is applied by injecting the coating composition under pressure into the gap between the surface of the substrate and the inner wall of the cavity. The pressure is high enough for the cavity, which is pressurized due to an external pressure device, such as clamps (as described in more detail below), to be filled before the end of the pot life of the coating composition is reached. At the same time, the pressure prevents the formation of bubbles at the flow front of the coating composition.

[0105] Curing of the coating composition is also carried out under pressure. In the context of the present invention, curing of the coating composition means that the coating has cured to an extent sufficient so that upon opening of the mold, the coated molded substrate releases, i.e., demolds, from the mold by the force of gravity alone or with suction alone when the mold is opened. At the end of the curing time, the pressure in the cavity may have fallen to ambient pressure.

[0106] Several factors contribute to the ability to conduct an in-mold coating process in which upon opening a mold cavity, the coated mold plastic substrate releases, i.e., demolds, from the internal surface of the second mold by the force of gravity alone or, at most, a suction force alone when the mold is opened, and without any additional force or effort being required to remove the coated molded substrate from the cavity. In particular, a combination of mold temperature, external mold pressure, cure time, the composition of the coating itself (including the presence of an internal mold release agent as described above and the ratio of isocyanate groups to isocyanate-reactive groups described earlier), and the presence of the external mold release agent described below each can be a significant contributor to the ability of a coated molded substrate to demold from the second mold cavity via gravity alone or with suction alone after the coating composition has cured and the mold is opened.

[0107] More particularly, the coating composition (including the presence of an internal mold release agent as described above and the ratio of isocyanate groups to isocyanate-reactive groups described earlier) and the selected combination of cure time, mold temperature and external mold pressure used are selected so that urea groups of the polyurethanes chains in the cured coating are crosslinked with one another in the coating, thereby increasing the crosslink density of the polyurethane polymeric network. It is believed that this crosslinking of the polyurethane chains can be measured by analyzing the content of free urea groups in the cured coating when the mold is opened.

[0108] The coating composition is injected into a mold cavity. The mold cavity may be of any desired design, so that the coating layer is, if desired, the same thickness over the entire surface of the substrate, also known as a “conformal coating.” In other cases, if desired, the cavity may be shaped such that the coating layer is of a different thickness in various regions of the substrate, such having one thickness when it is encapsulating a sensitive additional component, and another when it is only covering the substrate. For example, the mold cavity may be shaped to give a substantially smooth surface at a constant distance from the substrate, even in places where the substrate includes additional components. This also is known as a “non-conformal coating.” A substantially smooth surface appears where the distance between the substrate and the coating surface is at a substantially constant distance, with a 10% or less deviation, preferably a 5% or less deviation. In some cases, the mold cavity may have a textured surface or may have a desired design or logo that is sought to be included in the coating. The desired coating layer thickness may be achieved at any point of the substrate in this manner. In certain embodiments of the present invention, an external release agent is present on the surface of one or both of the cavities. In particular, a coating comprising electroless nickel and polytetrafluoroethylene (PTFE) is suitable as an external release agent. Such a coating is commercially available under the tradename Poly-Ond® from Poly-Plating, Inc. In certain embodiments of the present invention, the mold cavity is designed such that the dry film thickness of the coating layer that is produced is 0.05 to 3.5 millimeters, preferably 0.5 to 3.0 millimeters.

[0109] Injection of the coating composition into the mold cavity can be accomplished via injection of the composition into the cavity via one or more nozzles such that the gap between the surface of the molded substrate and mold inner w all is filled completely with the coating composition. For an optimum injection of the coating composition, the number and position of the injection points can be chosen appropriately in a manner known to the person skilled in the art. The mold cavity may be designed so as to provide a controlled displacement of the air present in the cavity and its removal via a parting line or venting channels during the injection. Known calculation programs may be used for this. The sprue design for injection of the coating composition may be e.g. according to the sprue variants known from the prior art for the production of RIM moldings. [0110] In certain embodiments, the coating is carried out by the RIM process with a single cavity. This has the advantage that the two components of the two-component of the coating composition are combined only immediately before injection into the cavity. In certain embodiments, this is accomplished by feeding a component comprising an isocyanate-reactive resin (as described above) and a component comprising a polyisocyanate (as described above) from a RIM installation into an impingement mixing head where the components are mixed before injection into the mold cavity. Typically each of the components is fed to the impingement mixing head through an orifice having a diameter of 0.15 mm - 0.70 mm.

[OHl] In embodiments of the present invention, the mixture is injected into the second mold cavity at a flow rate of 10-60 grams/ second, preferably 15-40 grams/second, at a line pressure of 1600 to 3000 psi (11,000 to 20,700 kPa), preferably 1800 to 2200 psi (12,400 to 15,200 kPa) and at a temperature of 50-120°C (120-248°F), preferably 50-80°C (120-177°F), most preferably 66-77°C (150-170°F). While the line pressures above may seem high, it is understood that the delicate additional components inside the mold cavity would not face such pressures, after the coating composition is injected. Rather, the pressure inside the cavity is expected to be significantly lower. The mixture preferably has a viscosity of 200 - 500 mPa s (200 - 500 cP) at processing temperature. The lower viscosity of the mixture, combined with the higher injection temperature, lowers the forces that are applied to the additional components, while at the same time ensure the mixture forms the expected coating or encapsulation of the additional components.

[0112] Once the coating composition is in the mold cavity, it is exposed to cure conditions of elevated temperature and external mold pressure.

[0113] Suitable mold temperatures for use in the present invention range, for example, from 62 to 105°C, preferably 71 to 82°C (160 - 180°F). As used herein, “external mold pressure’' means the externally applied pressure applied against the opposing faces of the mold (in which the cavity is disposed) when the opposing faces of the mold are forced together. The source of such pressure can be clamps, rams, or another device. In certain embodiments, the external mold pressure is at least 100 kg/mm2 (9807 bar), such as at least 110 (10787 bar), or at least 120 kg/mm2 (11768 bar). In certain of these embodiments, the external mold pressure is no more than 200 kg/mm2 (19613 bar), such as no more than 180 (17652 bar) or no more than 160 kg/mm2 (15691 bar). The external mold pressure, in certain embodiments, is maintained relatively constant through the coating cure process. In certain embodiments, the reaction, i.e.. cure, time is at least 60 seconds, such as at least 70 seconds. In some of these embodiments, the cure time is no more than 120 seconds.

[0114] As will be appreciated, the process according to the invention may also be carried out in a mold having more than the two cavities. Thus, for example, the additional components may be applied in another cavity. Also, further coating layers with optionally specific properties may be applied by applying each coating layer in its own cavity. It is furthermore possible to produce several molded plastic substrates in parallel in one cavity each and then to coat these successively in one cavity or in parallel in one cavity each.

EXAMPLE

[0115] As shown in Fig. 1. film 10 comprises side 12. onto which there are several features including holes 14, LEDs 16 and connector 18. Fig. 2 shows the same film 10 and connector 18 of Fig. 1, but in a perspective view where further elements of connector 18 may be seen, including connector outer surface 20, connector inner surface 22 and connector prongs 24. Figs. 3 and 4 show separate reinforcement piece 30 from two different angles. Separate reinforcement piece 30 has an outer surface 32. and openings 34 and 36. The opening may be sized, such that they do not interfere with any connector prongs, such as connector prongs shown in Fig. 2, when the separate reinforcement piece is placed inside of the connector.

[0116] Figs. 5 and 6 show film 40, which comprises side 46, holes 42 and LEDs 44. Film 40 also comprises connector 48, into which separate reinforcement piece 50 fits. A portion of outer surface 52 of connector 50 is in contact with at least two inner surfaces of connector 48, wherein the surfaces of connector 48 and separate reinforcement piece 50 that are in contact, are preferably opposite from each other. Separate reinforcement piece 50 is shown with holes 54 that may be used in placing it inside of, and removing it from, connector 48.

[0117] With the separate reinforcement piece in place, film 40 is prepared for the next molding or coating step. The sizing and placement of separate reinforcement piece 50 is preferred, such that during a subsequent molding or coating step where the film may experience elevated pressures on the other side of film 40, the pressure against connector 48 would be dissipated and absorbed. In this way, the pressure from a molding or coating step would not deform connector 48. In an embodiment where pressure is coming from the opposite side of film 40, opposite from side 46, then the pressure will go through connector 48, against the surfaces to separate reinforcement piece 50, and against the top of connector 48. In this way, it preserves the shape of connector 48, so it may receive an equally shaped male connector piece when it is put into operation in its intended use.

Claims

WHAT IS CLAIMED IS;

1. A process for insert molding comprising:

(a) introducing a film having a first side and a second side, wherein the first side has an element with an opening attached thereto, into a mold cavity of a mold;

(b) inserting a separate reinforcement piece inside of the opening of the element;

(c) introducing a thermoplastic composition onto the second side of the film;

(d) back molding the film wi th the thermoplastic composition, wherein pressure of the thermoplastic composition against the second side of the film is 5,000 kPa to 15,000 kPa, preferably 7.000 kPa to 15,000 kPa;

(e) cooling the thermoplastic composition in the mold cavity to at or below 50°C; and

(f) removing the separate reinforcement piece from the opening of the element.

2. The process of claim 1. wherein the film comprises polyamide or polycarbonate.

3. The process of one of claims 1 and 2, wherein the element with an opening is at least one of electronic circuits, light emitting diodes and female connectors.

4. The process of any one of the preceding claims, wherein the element with an opening is exposed to a pressure during back molding step (d) of 5,000 kPa to 15,000 kPa.

5. The process of any one of the preceding claims, wherein the element with an opening is in contact with the first side of the film during back molding step (d).

6. The process of any one of the preceding claims, wherein the element with an opening is a female connector.

7. The process of any one of the preceding claims, wherein the separate reinforcement piece comprises a metal, a structural polymer, wood, rigid foam, or rigid elastomers.

8. The process of any one of the preceding claims, wherein the separate reinforcement piece comprises or consists of aluminum.

9. The process of any one of the preceding claims, wherein the separate reinforcement piece comprises or consists of an epoxy.

10. The process of any one of the preceding claims, wherein the film has at least two elements with an opening attached thereto, and wherein the separate reinforcement piece is inserted into each opening of the at least two elements.

11. The process of any one of the preceding claims, wherein the thermoplastic composition comprises polycarbonate.

12. The process of any one of the preceding claims, wherein the thermoplastic composition further comprises a filler selected from the group consisting of glass, graphite, talc, and titanium dioxide.

13. The process of any one of the preceding claims, wherein the thermoplastic composition is introduced at a temperature of 260°C-350°C, preferably 280°C-330°C.

14. The process of any one of the preceding claims, wherein the process further comprises the step of adding a pressure-sensitive adhesive to the second side of the film, before introducing the thermoplastic composition to the film.

15. A process for in-mold coating comprising:

(a) introducing a substrate comprising an element attached thereto, the element having an exterior surface and an opening exposing an interior surface, into a mold cavity of a mold;

(b) inserting a separate reinforcement piece inside of the opening of the element;

(c) introducing a coating composition into the mold cavity containing the substrate;

(d) coating the substrate at a processing temperature, and at a processing pressure of 11,000 20,700 kPa to 20,700 kPa;

(e) curing the coating composition in the mold cavity⁷ at cure temperature of 62°C- 105°C; and

(1) removing the separate reinforcement piece from the opening of the element, wherein the exterior surface of the element is exposed to the coating composition, and wherein the coating composition after curing has a thickness of 0.05 mm to 3.5 mm.

16. The process of claim 15, wherein the substrate comprises aromatic polycarbonate.

17. The process of one of claims 15 and 16, wherein the element with an opening is at least one of electronic circuits, light emitting diodes and female connectors.

18. The process of any one of claims 15 to 17, wherein the element with an opening is a female connector.

19. The process of any one of claims 15 to 18. wherein the separate reinforcement piece comprises a metal, a structural polymer, wood, rigid foam or rigid elastomers.

20. The process of any one of claims 15 to 19, wherein the separate reinforcement piece comprises or consists of aluminum.

21. The process of any one of claims 15 to 20, wherein the separate reinforcement piece comprises or consists of an epoxy.

22. The process of any one of claims 15 to 21. wherein the substrate has at least two elements with an opening attached thereto, and wherein the separate reinforcement piece is inserted into each opening of the at least two elements.

23. The process of any one of claims 15 to 22. wherein the coating composition comprises (i) a polymer comprising isocyanate-reactive groups and (ii) a polyisocyanate.

24. The process of claim 23, wherein the polymer comprising isocyanate-reactive groups comprises an aromatic branched polyester polyol and an aliphatic polycarbonate polyol.

25. The process of claim 24, wherein the aliphatic polycarbonate polyol is a polycarbonate diol.

26. The process of any one of claims 23 to 25, wherein the polyisocyanate comprises an isocyanurate of hexamethylene diisocyanate.

27. The process of any one of claims 15 to 26, wherein the coating composition further comprises a plasticizer.

28. The process of any one of claims 15 to 27. wherein the coating composition has a viscosity of 200 mPa s to 500 mPa s at the processing temperature.

29. The process of any one of claims 15 to 28, wherein the coating composition has a thickness of 0.5 mm - 3.0 mm.

30. The process of any one of claims 15 to 29, wherein the processing temperature is 50°C-120°C, preferably 50°C-80°C, most preferably 66°C-77°C.

31. The process of any one of claims 15 to 30, wherein the processing pressure is 12,400 kPa to 15,200 kPa.

32. The process of any one of claims 15 to 31, wherein the mold cavity is at a mold temperature of 71 °C to 82°C.