Foaming agent for thermoplastic foam, thermoplastic foam and foaming method

Abstract

A method for forming an extruded polystyrene foam comprises: (a) providing a thermoplastic melt and a blowing agent in the melt, the blowing agent comprising: (1) from about 10% to about 50% by weight of HCFO-1233zd (E); (2) from about 35% by weight to about 75% by weight of HFC-134a; (3) from about 10% to about 30% by weight of isobutane; and (4) optionally up to about 15% by weight of dimethyl ether; and (b) foaming the thermoplastic material.

Description

Technical Field

[0001] The present invention relates to compositions, methods and systems useful in connection with extruded thermoplastic foams, including, in particular, with blowing agents, foamable compositions, foams and articles made with or from polystyrene foams. Background Art

[0002] Certain fluorocarbon fluids have found widespread use as blowing agents. Due to environmental concerns associated with the use of some of these fluorocarbon fluids, including relatively high ozone depletion potential, there is an increasing desire to use fluids with low or even zero ozone depletion potential, such as hydrofluorocarbons ("HFCs"). However, some HFC fluids may have relatively high global warming potentials associated with them, and it is desirable to use hydrofluorocarbons or other fluorinated fluids with low ozone depletion potential and low global warming potential while maintaining desired foam performance characteristics.

[0003] With respect to the performance properties of foams, it is often considered important that the foam possess excellent thermal insulation properties and other desirable foam characteristics. Another foam characteristic that is important in many applications is the density of the foam. For example, in many insulating foam applications, it is desirable to have a foam that exhibits not only low thermal conductivity but also a relatively low foam density.

[0004] In an effort to obtain thermoplastic foams having both low thermal conductivity (measured after aging) and low density at once, and in particular a density of less than 40 kg / m 3 Significant challenges have been encountered in producing thermoplastic polystyrene foams that simultaneously have an aged thermal conductivity of 29.5 mW / mK or less.

[0005] Thus, there is a growing need for new blowing agent materials that are attractive alternatives to compositions heretofore used as blowing agents in these and other applications. Accordingly, Applicants have recognized a need for new blowing agent compositions that provide effective alternatives to, and are considered to be environmentally safer alternatives to, previously used blowing agents for preparing low density, low thermal conductivity thermoplastic foams, particularly extruded polystyrene foams.

[0006] The use of halogenated olefin blowing agents, including hydrofluoroolefins (HFOs) and hydrochlorofluoroolefins (HCFOs), is also known, as disclosed, for example, in US 2009 / 0305876, assigned to the assignee of the present invention and incorporated herein by reference.

[0007] Despite the disclosure in the '876 publication, Applicants have recognized that by using a combination of carefully selected amounts of carefully selected blowing agent components, unexpected advantages can be realized in forming extruded thermoplastic foams, and particularly extruded polystyrene foams, as explained in detail below. SUMMARY

[0008] The present invention includes blowing agent formulations for producing thermoplastic foams having excellent thermal insulation properties, preferably including low initial lambda and delta lambda (as defined below), and low foam density, said blowing agent formulations comprising:

[0009] (a) from about 10 to about 50 weight percent HCFO-1233zd(E);

[0010] (b) from about 30 to about 65 weight percent HFC-134a;

[0011] (c) from about 10 to about 30 weight percent isobutane;

[0012] (d) optionally up to about 15 weight percent dimethyl ether; and

[0013] (e) optionally up to about 10 weight percent CO2 or water or ethanol or combinations thereof, wherein the amount of components (a)-(e) in the blowing agent is no less than about 95 weight percent of all blowing agent components in the formulation. For convenience, blowing agents according to this paragraph are referred to herein as Blowing Agent 1A1.

[0014] The present invention includes blowing agent formulations for producing thermoplastic foams having excellent thermal insulation properties, preferably including low initial lambda and delta lambda (as defined below), and low foam density, said blowing agent formulations comprising:

[0015] (a) from about 10 to less than 35 weight percent HCFO-1233zd(E);

[0016] (b) from about 30 to about 65 weight percent HFC-134a;

[0017] (c) from about 15 to about 25 weight percent isobutane;

[0018] (d) optionally up to about 20 weight percent of a fourth component comprising dimethyl ether or di

[0019] oxidized carbon or water or ethanol or combinations thereof,

[0020] wherein the amount of components (a)-(d) in the blowing agent is no less than about 95 weight percent of all blowing agent components in the formulation. For convenience, blowing agents according to this paragraph are referred to herein as Blowing Agent 1A2.

[0021] The present invention comprises a blowing agent formulation for producing a thermoplastic foam having excellent thermal insulation properties, preferably including low initial lambda and delta lambda (as defined below), and low foam density, the blowing agent formulation comprising:

[0022] (a) from about 10 wt% to about 30 wt% HCFO-1233zd(E);

[0023] (b) from about 35 weight percent to about 65 weight percent HFC-134a;

[0024] (c) from about 10 weight percent to about 30 weight percent isobutane; and

[0025] (d) optionally up to about 20% by weight of a fourth component comprising dimethyl ether or dimethyl ether

[0026] carbon dioxide or water or ethanol or a combination thereof,

[0027] wherein the amount of components (a)-(d) in the blowing agent is not less than about 95% by weight of all blowing agent components in the formulation.For convenience, the blowing agent according to this paragraph is referred to herein as blowing agent 1A3.

[0028] The present invention also includes a blowing agent formulation for producing a thermoplastic foam having excellent thermal insulation properties, preferably including low aged lambda (as defined below), and low foam density, the blowing agent formulation comprising:

[0029] (a) from about 10 wt% to about 35 wt% HCFO-1233zd(E);

[0030] (b) from about 40 weight percent to about 65 weight percent HFC-134a;

[0031] (c) from about 10 weight percent to about 30 weight percent isobutane; and

[0032] (d) optionally up to about 15% by weight of dimethyl ether; and

[0033] (e) optionally up to about 10 wt % carbon dioxide or water or ethanol or a combination thereof, wherein the amount of components (a)-(e) is not less than about 95 wt % of all blowing agent components in the formulation. For convenience, the blowing agent according to this paragraph is referred to herein as blowing agent 2A1.

[0034] The present invention also includes a blowing agent formulation for producing a thermoplastic foam having excellent thermal insulation properties, preferably including low aged lambda (as defined below), and low foam density, the blowing agent formulation comprising:

[0035] (a) from about 10 wt% to about 28 wt% HCFO-1233zd(E);

[0036] (b) from about 40 weight percent to about 65 weight percent HFC-134a;

[0037] (c) from about 10 weight percent to about 30 weight percent isobutane; and

[0038] (d) optionally up to about 15% by weight of dimethyl ether; and

[0039] (e) optionally up to about 10 wt % carbon dioxide or water or ethanol or a combination thereof, wherein the amount of components (a)-(e) is not less than about 95 wt % of all blowing agent components in the formulation. For convenience, the blowing agent according to this paragraph is referred to herein as blowing agent 2A2.

[0040] The present invention also includes a blowing agent formulation for producing a thermoplastic foam having excellent thermal insulation properties, preferably including low aged lambda (as defined below), and low foam density, the blowing agent formulation comprising:

[0041] (a) from about 10 wt% to about 27 wt% HCFO-1233zd(E);

[0042] (b) from about 40 weight percent to about 65 weight percent HFC-134a;

[0043] (c) from about 10 weight percent to about 30 weight percent isobutane; and

[0044] (d) optionally up to about 15% by weight of dimethyl ether; and

[0045] (e) optionally up to about 10 wt % carbon dioxide or water or ethanol or a combination thereof, wherein the amount of components (a)-(e) is not less than about 95 wt % of all blowing agent components in the formulation. For convenience, the blowing agent according to this paragraph is referred to herein as blowing agent 2A3.

[0046] The present invention also includes a blowing agent formulation for producing a thermoplastic foam having excellent thermal insulation properties, preferably including low aged lambda (as defined below), and low foam density, the blowing agent formulation comprising:

[0047] (a) from about 10 wt% to about 30 wt% HCFO-1233zd(E);

[0048] (b) from about 40 weight percent to about 65 weight percent HFC-134a;

[0049] (c) from about 10% to about 27% by weight of isobutane; and

[0050] (d) optionally up to about 15% by weight dimethyl ether; and

[0051] (e) optionally up to about 10% by weight carbon dioxide or water or ethanol or a combination thereof, wherein the amount of components (a)-(e) is no less than about 95% by weight of all blowing agent components in the formulation. For convenience, the blowing agent according to this paragraph is referred to herein as Blowing Agent 2A2.

[0052] The present application also includes blowing agent formulations for producing thermoplastic foams having excellent thermal insulation properties, preferably including low aged lambda (as defined below), and low foam density, said blowing agent formulations comprising:

[0053] (a) about 10% to about 26% by weight HCFO-1233zd(E);

[0054] (b) about 40% to about 65% by weight HFC-134a;

[0055] (c) about 10% to about 30% by weight isobutane; and

[0056] (d) optionally up to about 15% by weight dimethyl ether; and

[0057] (e) optionally up to about 10% by weight carbon dioxide or water or ethanol or a combination thereof, wherein the amount of components (a)-(e) is no less than about 95% by weight of all blowing agent components in the formulation. For convenience, the blowing agent according to this paragraph is referred to herein as Blowing Agent 2A4.

[0058] The present application also includes blowing agent formulations for producing thermoplastic foams having excellent thermal insulation properties, preferably including low aged lambda (as defined below), and low foam density, said blowing agent formulations comprising:

[0059] (a) about 10% to about 25% by weight HCFO-1233zd(E);

[0060] (b) about 40% to about 65% by weight HFC-134a;

[0061] (c) about 10% to about 30% by weight isobutane; and

[0062] (d) optionally up to about 15% by weight dimethyl ether; and

[0063] (e) optionally up to about 10% by weight carbon dioxide or water or ethanol or a combination thereof, wherein the amount of components (a)-(e) is no less than about 95% by weight of all blowing agent components in the formulation. For convenience, the blowing agent according to this paragraph is referred to herein as Blowing Agent 2A5.

[0064] The present invention also includes a foamable thermoplastic composition comprising:

[0065] (a) a foamable thermoplastic polymer in a molten state; and

[0066] (b) a blowing agent formulation in the foamable thermoplastic polymer, wherein the blowing agent formulation is any one or more of Blowing Agent 1 to Blowing Agent 2. For convenience, the blowing agent according to this paragraph is referred to herein as Foamable Composition 1.

[0067] As used herein, reference to a defined blowing agent or a series of defined blowing agents, such as blowing agent 1 through blowing agent 2, includes all blowing agents so defined, including any numbered blowing agents including suffixes. For example, reference to blowing agent 1 specifically includes each of blowing agent 1A1, blowing agent 1A2, and blowing agent 1A3.

[0068] The present invention also includes a foamable thermoplastic composition comprising:

[0069] (a) expandable polystyrene in a molten state; and

[0070] (b) a blowing agent formulation in the foamable thermoplastic polymer, wherein the blowing agent formulation is any one or more of Blowing Agent 1 to Blowing Agent 2. For convenience, the blowing agent according to this paragraph is referred to herein as Foamable Composition 2.

[0071] The present invention also includes a method of forming a foam, the method comprising:

[0072] (a) providing a foamable composition of the present invention, comprising foamable composition 1 and foamable composition 2; and

[0073] (b) foaming the foamable composition. For convenience, the method according to this paragraph is referred to herein as Foaming Method 1.

[0074] The present invention also includes a method of forming a foam, the method comprising:

[0075] (a) providing a foamable composition of the present invention, comprising foamable composition 1 and foamable composition 2; and

[0076] (b) foaming the foamable composition by a process comprising extruding the foamable composition.

[0077] For convenience, the method according to this paragraph is referred to herein as Foaming Method 2.

[0078] The present invention also includes a thermoplastic foam comprising:

[0079] (a) a thermoplastic foam comprising a plurality of closed cells; and

[0080] (b) a gaseous material contained in the closed cells, the gaseous material comprising the foamed

[0081] Agent, including each of Blowing Agent 1 to Blowing Agent 2. For convenience, the foam according to this paragraph is referred to herein as Foam 1A.

[0082] The present invention also includes a thermoplastic foam comprising:

[0083] (a) a thermoplastic foam comprising a plurality of closed polystyrene cells; and

[0084] (b) a gaseous material contained in the closed cells, the gaseous material comprising the foamed

[0085] Agent, including each of Blowing Agent 1 to Blowing Agent 2. For convenience, the foam according to this paragraph is referred to herein as Foam 1B.

[0086] The present invention also includes a thermoplastic foam comprising:

[0087] (a) a thermoplastic foam comprising a plurality of closed cells; and

[0088] (b) a gaseous material contained in the closed cells, the gaseous material comprising the foamed

[0089] agent, including each of blowing agent 1 to blowing agent 2, wherein the foam has a foaming capacity of not more than 40 kg / m 3 and an aged thermal conductivity of no greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 2A.

[0090] The present invention also includes a thermoplastic foam comprising:

[0091] (a) a thermoplastic foam comprising a plurality of closed cells; and

[0092] (b) a gaseous material contained in the closed cells, the gaseous material comprising the foamed

[0093] agent, including each of blowing agent 1 to blowing agent 2, wherein the foam has a pressure of not more than 39 kg / m 3 and an aged thermal conductivity of no greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 2B.

[0094] The present invention also includes a thermoplastic foam comprising:

[0095] (a) a thermoplastic foam comprising a plurality of closed cells; and

[0096] (b) a gaseous material contained in the closed cells, the gaseous material comprising the foamed

[0097] agent, including each of blowing agent 1 to blowing agent 2, wherein the foam has a foaming capacity of not more than 38 kg / m 3 and an aged thermal conductivity of no greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 2C.

[0098] The present invention also includes a thermoplastic foam comprising:

[0099] (a) a thermoplastic foam comprising a plurality of closed cells; and

[0100] (b) a gaseous material contained in the closed cells, the gaseous material comprising the foamed

[0101] agent, including each of blowing agent 1 to blowing agent 2, wherein the foam has a pressure of not more than 37 kg / m 3 and an aged thermal conductivity of no greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 2D.

[0102] The present invention also includes a thermoplastic foam comprising:

[0103] (a) a thermoplastic foam comprising a plurality of closed cells; and

[0104] (b) a gaseous material contained in the closed cells, the gaseous material comprising the foamed

[0105] agent, including each of blowing agent 1 to blowing agent 2, wherein the foam has a pressure of not more than 36 kg / m 3 and an aged thermal conductivity of no greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 2E.

[0106] The present invention also includes a thermoplastic foam comprising:

[0107] (a) a thermoplastic foam comprising a plurality of closed cells; and

[0108] (b) a gaseous material contained in the closed cells, the gaseous material comprising the foamed

[0109] agent, including each of blowing agent 1 to blowing agent 2, wherein the foam has a foaming capacity of not more than 35 kg / m 3density of not greater than 39 kg / m and an aged thermal conductivity of not greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 3B.

[0110] The present application also includes a polystyrene foam comprising:

[0111] (a) a thermoplastic foam comprising a plurality of polystyrene closed cells; and

[0112] (b) a gaseous material contained within the closed cells, the gaseous material comprising a blowing agent of the present application including each of Blowing Agent 1 through Blowing Agent 2, wherein the foam has a density of not greater than 39 kg / m and an aged thermal conductivity of not greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 3B.

[0113] (b) a gaseous material contained within the closed cells, the gaseous material comprising a blowing agent of the present application including each of Blowing Agent 1 through Blowing Agent 2, wherein the foam has a density of not greater than 39 kg / m and an aged thermal conductivity of not greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 3B. 3

[0114] The present application also includes a polystyrene foam comprising:

[0115] (a) a thermoplastic foam comprising a plurality of polystyrene closed cells; and

[0116] (b) a gaseous material contained within the closed cells, the gaseous material comprising a blowing agent of the present application including each of Blowing Agent 1 through Blowing Agent 2, wherein the foam has a density of not greater than 39 kg / m and an aged thermal conductivity of not greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 3B.

[0117] (b) a gaseous material contained within the closed cells, the gaseous material comprising a blowing agent of the present application including each of Blowing Agent 1 through Blowing Agent 2, wherein the foam has a density of not greater than 39 kg / m and an aged thermal conductivity of not greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 3B. 3

[0118] The present application also includes a polystyrene foam comprising:

[0119] (a) a thermoplastic foam comprising a plurality of polystyrene closed cells; and

[0120] (b) a gaseous material contained within the closed cells, the gaseous material comprising a blowing agent of the present application including each of Blowing Agent 1 through Blowing Agent 2, wherein the foam has a density of not greater than 39 kg / m and an aged thermal conductivity of not greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 3B.

[0121] (b) a gaseous material contained within the closed cells, the gaseous material comprising a blowing agent of the present application including each of Blowing Agent 1 through Blowing Agent 2, wherein the foam has a density of not greater than 39 kg / m and an aged thermal conductivity of not greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 3B. 3

[0122] The present application also includes a polystyrene foam comprising:

[0123] (a) a thermoplastic foam comprising a plurality of polystyrene closed cells; and ​​​

[0124] (b) a gaseous material contained in the closed cells, the gaseous material comprising the blowing agent of the present invention, including each of blowing agent 1 to blowing agent 2, wherein the foam has a mass fraction of not more than 37 kg / m 3 and an aged thermal conductivity of no greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 3D.

[0125] The present invention also includes a polystyrene foam comprising:

[0126] (a) a thermoplastic foam comprising a plurality of closed polystyrene cells; and

[0127] (b) a gaseous material contained in the closed cells, the gaseous material comprising the blowing agent of the present invention, including each of blowing agent 1 to blowing agent 2, wherein the foam has a mass fraction of not more than 36 kg / m 3 and an aged thermal conductivity of no greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 3E.

[0128] The present invention also includes a polystyrene foam comprising:

[0129] (a) a thermoplastic foam comprising a plurality of closed polystyrene cells; and

[0130] (b) a gaseous material contained in the closed cells, the gaseous material comprising the blowing agent of the present invention, including each of blowing agent 1 to blowing agent 2, wherein the foam has a mass fraction of not more than 35 kg / m 3 and an aged thermal conductivity of no greater than 29.5 mW / mK. For convenience, the foam according to this paragraph is referred to herein as Foam 3F. BRIEF DESCRIPTION OF THE DRAWINGS

[0131] Figure 1 is a schematic diagram of an extrusion system and method according to one embodiment of the present invention and according to the Examples herein.

[0132] Figure 2 is a graph showing the results of comparative examples and examples of the present invention as described herein.

[0133] definition

[0134] HFC-134a and 134a refer to 1,1,1,2-tetrafluoroethane.

[0135] Isobutane and iC4 and isoC4 each refer to 2-methylpropane.

[0136] 1233zd refers to 1-chloro-3,3,3-trifluoropropene, with no restriction on isomeric forms.

[0137] Trans 1233zd and 1233zd(E) each refer to trans 1-chloro-3,3,3-trifluoropropene.

[0138] Cis 1224yd refers to cis 1-chloro-2,3,3,3-tetrafluoropropane.

[0139] 1234ze refers to 1,1,1,3-tetrafluoropropene, without restriction as to the isomeric form.

[0140] Trans 1234ze and 1234ze(E) each refer to trans 1,3,3,3-tetrafluoropropene.

[0141] Cis 1336mzz and 1336mzz(Z) each refer to cis-1,1,1,4,4,4-hexafluorobutene.

[0142] Trans 1336mzz and 1336mzz(E) each refer to trans 1,1,1,4,4,4-hexafluorobutene.

[0143] Methyl formate refers to the following compound

[0144] Methylal refers to dimethyloxymethane ((CH3O)2CH2).

[0145] Dimethyl ether and DME each refer to the following compound

[0146] Isobutane and iC4 and isoC4 each refer to 2-methylpropane.

[0147] Ethanol and EtOH each refer to CH3CH2OH.

[0148] Closed cell foam refers to a foam in which a substantial volume percentage of the cells are closed, e.g., about 20 vol% or more.

[0149] Styrene moieties refer to compounds having the structure

[0150]

[0151] as well as all compounds in which one or more hydrogens are replaced by a substituent.

[0152] Polystyrene, polystyrene resin, and PS each refer to polymers prepared from monomers comprising styrene moieties, including homopolymers, copolymers thereof, and blends of polymers including such homopolymers and / or copolymers.

[0153] XPS foam refers to polystyrene that has been foamed in an extrusion process.

[0154] Aged thermal conductivity and aged λ each refer to the thermal conductivity measured as described in the Examples.

[0155] Density refers to the foam density as measured in the examples.

[0156] A blowing agent formulation refers to a component or combination of components used and / or intended for use in foaming a foamable material, including such combinations of components that are introduced into the foamable material at different times and / or locations. Thus, the term is intended to encompass the situation where a first blowing agent component and a second blowing agent component are present in a foamable composition during an extrusion process, wherein the first blowing agent component is introduced into the foamable composition at a first, relatively upstream location during the extrusion process, and the second component is introduced into the foamable composition at a second, relatively downstream location during the extrusion process. DETAILED DESCRIPTION

[0157] foaming agent

[0158] The blowing agents of the present invention (including each of Blowing Agent 1 to Blowing Agent 2) may include one or more co-blowing agents other than those specified, provided that their type and amount do not impair the ability of the blowing agent to form thermoplastic foam, preferably polystyrene foam, and particularly XPS foam, and preferably do not prevent the foam from exhibiting one or more of the density and thermal conductivity properties described herein as aspects of the invention. Within this parameter, and by way of example only, the blowing agents of the present invention (including each of Blowing Agents 1 to 2) may also include: (1) one or more of the following: saturated hydrocarbons having 3 to 5 carbon atoms, such as propane, n-butane, and cyclopentane; (2) ethers, such as diethyl ether, diethyl ether, and methyl ethyl ether; (3) alkyl chlorides, such as methyl chloride and ethyl chloride; (4) alcohols, such as methanol, propanol, isopropanol, butanol, sec-butanol, tert-butanol, aryl alcohols, crotyl alcohol, and propargyl alcohol; (5) ketones; (6) esters; and halogenated C1-C5 olefins, including 1234ze, 1224yd, and 1336mzz.

[0159] Other additives may also be included, again to the extent that their types and amounts do not impair the ability of the blowing agent to form polystyrene foam, particularly XPS foam, having the density and thermal conductivity characteristics described herein as aspects of the present invention. Within this parameter, and by way of example only, the blowing agent of the present blowing agent of the present invention (including each of Blowing Agent 1 to Blowing Agent 2) may include one or more of the following: processing aids, flame retardants, colorants, stabilizers, surfactants, polymer modifiers, toughening agents, colorants, dyes, solubility enhancers, rheology modifiers, plasticizers, flammability inhibitors, biocides, viscosity reducing modifiers, fillers, vapor pressure modifiers, nucleating agents, catalysts, and the like.

[0160] Foamable composition

[0161] The present invention also includes a foamable thermoplastic composition comprising a thermoplastic polymer and a blowing agent in the thermoplastic polymer. The present invention includes foamable compositions, including foamable polystyrene compositions, comprising a blowing agent as identified in the following table of foamable compositions (using the blowing agent numbers as defined above):

[0162] Table of foamable compositions

[0163]

[0164]

[0165] There are no particular limitations on the styrene resins used in the present invention (including the foamable compositions identified above and in the table of foamable compositions above, or the foams identified above or in the table of XPS foams below), and examples of the styrene resins include: homopolymers of styrene monomers such as styrene, methylstyrene, ethylstyrene, isopropylstyrene, dimethylstyrene, bromostyrene, chlorostyrene, vinyltoluene, and vinylxylene; or copolymers of two or more of the monomers; copolymers obtained by copolymerizing a styrene monomer with at least one or two or more of monomers such as divinylbenzene, butadiene, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, acrylonitrile, maleic anhydride, and itaconic anhydride. Monomers copolymerized with the styrene monomer (such as acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, maleic anhydride, and itaconic anhydride) may be used in an amount that does not impair the physical properties of the extruded polystyrene foam to be produced, such as compressive strength. The styrene resin used in the present invention is not limited to a homopolymer or copolymer of a styrene monomer and may be a blend of a homopolymer or copolymer of a styrene monomer with a homopolymer or copolymer of another monomer, and may be a blend of diene rubber-reinforced polystyrene or acrylic rubber-reinforced polystyrene. In order to adjust the melt volume rate (hereinafter also referred to as MVR), melt viscosity and melt tension during molding, etc., the styrene resin used in the present invention may be a styrene resin having a branched structure.

[0166] According to a preferred embodiment, the styrene resin used in the present invention, including each of the foamable compositions identified above and in the table of foamable compositions, or the foams identified above or in the table of XPS foams, is formed from a general-purpose styrene resin, preferably having an MVR of 0.1 g / 10 min to 50 g / 10 min. Such a resin is preferably used because it allows the thermoplastic resin foam to have excellent moldability during extrusion foam molding, the discharge rate during molding, and the thickness and width, apparent density, or closed cell ratio of the resulting extruded polystyrene foam to be adjusted to desired values. The MVR of the styrene resin may range from 0.3 g / 10 min to 30 g / 10 min, or from 0.5 g / 10 min to 25 g / 10 min. In the present invention, the MVR is measured according to ISO 1133.

[0167] In the present invention, among the above-mentioned styrene resins, polystyrene resin is suitable in terms of economic efficiency and processability. When higher heat resistance is required for extruded foam, styrene-acrylonitrile copolymer, (meth) acrylic acid copolymer polystyrene, maleic anhydride modified polystyrene are preferably used. When higher impact resistance is required for extruded foam, rubber reinforced polystyrene is preferably used. Styrene resin can be used alone, or two or more styrene resins having different copolymer components, molecular weight and molecular weight distribution, branched structure, MVR, etc. can be used as a mixture.

[0168] The PS used to form the foams of the present invention (including the foams identified in the XPS Foam Table above and in each of Foams 1 through 3) and used in accordance with the methods of the present invention (including each of Methods 1 through 2) can have properties within each of the broad, intermediate, and narrow ranges specified in the following table:

[0169]

[0170] Foam

[0171] The present invention also encompasses thermoplastic foams, including and preferably PS foam and even more preferably XPS foam, wherein the thermoplastic foam comprises polystyrene and a blowing agent of the present invention, including each of Blowing Agent 1 through Blowing Agent 2.

[0172] The present invention preferably comprises an XPS foam comprising:

[0173] (a) thermoplastic polymer pores, the thermoplastic polymer pores comprising pore walls forming closed pores, wherein the pore walls comprise polystyrene; and

[0174] (b) A blowing agent 1 contained in these closed cells. For convenience, the foam according to this paragraph is referred to herein as XPS foam 1.

[0175] The present invention comprises an XPS foam comprising:

[0176] (a) thermoplastic polymer pores, the thermoplastic polymer pores comprising pore walls forming closed pores, wherein the pore walls comprise polystyrene; and

[0177] (b) A blowing agent 2 contained in these closed cells. For convenience, the foam according to this paragraph is referred to herein as XPS foam 2.

[0178] method

[0179] Applicants have discovered that unexpected advantages can be achieved in preparing thermoplastic foams, including each of Foam 1 through Foam 3, by using the blowing agents of the present invention, including each of Blowing Agent 1 through Blowing Agent 2, in the foam formation process.

[0180] In a specific aspect, the present invention includes a method for preparing a thermoplastic XPS foam, the method comprising:

[0181] (i) provide PS; and

[0182] (ii) Foaming PS using any one of the blowing agents of the present invention (including each of blowing agent 1 to blowing agent 2). For convenience, the method according to this paragraph is referred to herein as foaming method 3.

[0183] The present invention also provides a method for forming an extruded thermoplastic foam, the method comprising:

[0184] (i) providing a thermoplastic material;

[0185] (ii) extruding thermoplastic materials; and

[0186] (iii) Foaming a thermoplastic material using any one of the blowing agents of the present invention (including each of Blowing Agent 1 to Blowing Agent 2). For convenience, the method according to this paragraph is referred to herein as Foaming Method 4.

[0187] The present invention also provides a method for forming XPS, the method comprising:

[0188] (i) providing thermoplastic polystyrene;

[0189] (ii) extruded thermoplastic polystyrene; and

[0190] (iii) Foaming polystyrene foam using any one of the blowing agents of the present invention (including each of blowing agent 1 to blowing agent 2). For convenience, the method according to this paragraph is referred to herein as foaming method 5.

[0191] The present application also provides a method for making an XPS foam, the method comprising:

[0192] (i) providing a PS; and

[0193] (ii) foaming the PS using any one of the blowing agents of the present application, including each of Blowing Agent 1 through Blowing Agent 2, wherein the foam has a density of about 37 kg / m3or less and an aged thermal conductivity of 30 mW / mk or less. For convenience, the method according to this paragraph is referred to herein as Foaming Method 6A.

[0194] The present application also provides a method for forming an extruded thermoplastic foam, the method comprising:

[0195] (i) providing a PS;

[0196] (ii) extruding the PS; and

[0197] (ii) foaming the PS using any one of the blowing agents of the present application, including each of Blowing Agent 1 through Blowing Agent 2, wherein the foam has a density of about 37 kg / m3or less and an aged thermal conductivity of 29.5 mW / mK or less. For convenience, the method according to this paragraph is referred to herein as Foaming Method 6B.

[0198] The present application also provides a method for forming an extruded thermoplastic foam, the method comprising:

[0199] (i) providing a PS;

[0200] (ii) extruding the PS; and

[0201] (iii) foaming the PS using any one of the blowing agents of the present application, including each of Blowing Agent 1 through Blowing Agent 4, wherein the foam has a density of about 37 kg / m3or less and an aged thermal conductivity of 29 mW / mK or less. For convenience, the method according to this paragraph is referred to herein as Foaming Method 6C.

[0202] The present application also provides a method for making a thermoplastic foam, including each of Methods 1 through 6, wherein the blowing agent is used in an amount of about 6 parts per hundred parts of the thermoplastic resin material (hereinafter referred to as “pph” or “pphr”) to about 12 pphr. For convenience, the method according to this paragraph is referred to herein as Method 7.

[0203] The present invention also provides a method for preparing thermoplastic foam, comprising each of methods 1 to 4, wherein the blowing agent is used in an amount of about 6 pphr to about 10 pphr. For convenience, the method according to this paragraph is referred to herein as method 8.

[0204] The present invention also provides a method for preparing thermoplastic foam, comprising each of methods 1 to 4, wherein the blowing agent is used in an amount of about 7 pphr to about 9 pphr. For convenience, the method according to this paragraph is referred to herein as method 9.

[0205] The present invention also provides a method for preparing a thermoplastic foam, comprising each of methods 1 to 9, wherein the step of providing the thermoplastic material or PS comprises including one or more optional components selected from surfactants, polymer modifiers, toughening agents, colorants, dyes, solubility enhancers, rheology modifiers, plasticizers, flammability inhibitors, biocides, viscosity reducing modifiers, fillers, vapor pressure modifiers, nucleating agents, catalysts, etc. in the thermoplastic material. For convenience, the method according to this paragraph is referred to herein as method 10.

[0206] The present invention also provides a method for forming an extruded thermoplastic foam, the method comprising:

[0207] (i) providing a melt comprising or consisting essentially of polystyrene and a blowing agent, the blowing agent including each of Blowing Agent 1 through Blowing Agent 2, wherein the blowing agent is present in the melt in an amount from about 6 pph to less than 12 pph;

[0208] (ii) extruding the melt; and

[0209] (iii) foaming the melt to form a slurry having a density of about 25 kg / m 3 to less than about 37 kg / m 3 and an extruded polystyrene foam having an aged thermal conductivity of less than about 30 mW / mK.For convenience, the method according to this paragraph is referred to herein as Method 11A.

[0210] The present invention also provides a method for forming an extruded thermoplastic foam, the method comprising:

[0211] (i) providing a melt comprising or consisting essentially of polystyrene and a blowing agent, the blowing agent including each of Blowing Agent 1 through Blowing Agent 4, wherein the blowing agent is present in the melt in an amount from about 6 pph to less than 10 pph;

[0212] (ii) extruding the melt; and

[0213] (iii) foaming the melt to form a mass fraction having a density of less than about 36 kg / m 3 and an extruded polystyrene foam having an aged thermal conductivity of about 30 mW / mK or less.For convenience, the method according to this paragraph is referred to herein as Method 11B.

[0214] The present invention also provides a method for forming an extruded thermoplastic foam, the method comprising:

[0215] (i) providing a melt comprising or consisting essentially of polystyrene and a blowing agent, the blowing agent including each of Blowing Agent 1 through Blowing Agent 2, wherein the blowing agent is present in the melt in an amount from about 6 pph to less than 10 pph;

[0216] (ii) extruding the melt; and

[0217] (iii) foaming the melt to form a slurry having a density of about 25 kg / m 3 To less than 35.5kg / m 3 and aging heat

[0218] Extruded polystyrene foam having a conductivity of about 25 mW / mK to less than 30 mW / mK or less

[0219] For convenience, the method according to this paragraph is referred to herein as method 11C. The present invention also provides a method for forming an extruded thermoplastic foam, the method comprising:

[0220] (i) providing a melt comprising or consisting essentially of polystyrene and a blowing agent, the blowing agent including each of Blowing Agent 1 through Blowing Agent 2, wherein the blowing agent is present in the melt in an amount from about 7 pph to less than 10 pph;

[0221] (ii) extruding the melt; and

[0222] (iii) foaming the melt to form a slurry having a density of about 25 kg / m 3 to less than about 35.5 kg / m 3 and an extruded polystyrene foam having an aged thermal conductivity of about 25 mW / mK to less than 29.5 mW / mK. For convenience, the method according to this paragraph is referred to herein as Method 11D.

[0223] The present invention also provides a method for forming an extruded thermoplastic foam, the method comprising:

[0224] (i) providing a melt comprising or consisting essentially of polystyrene and a blowing agent, the blowing agent including each of Blowing Agent 1 through Blowing Agent 2, wherein the blowing agent is present in the melt in an amount from about 6 pph to less than 10 pph;

[0225] (ii) extruding the melt; and

[0226] (iii) foaming the melt to form a slurry having a density of about 25 kg / m 3 To less than 36kg / m 3 and an extruded polystyrene foam having an aged thermal conductivity of about 25 mW / mK to less than about 28.5 mW / mK. For convenience, the method according to this paragraph is referred to herein as Method 1 IE.

[0227] The present invention also provides a method for forming an extruded thermoplastic foam, the method comprising:

[0228] (i) providing a melt comprising or consisting essentially of polystyrene and a blowing agent, the blowing agent including each of Blowing Agent 1 through Blowing Agent 2, wherein the blowing agent is present in the melt in an amount from about 6 pph to less than 10 pph;

[0229] (ii) extruding the melt; and

[0230] (iii) foaming the melt to form a slurry having a density of about 25 kg / m 3 To less than 35.5kg / m 3 and an extruded polystyrene foam having an aged thermal conductivity of about 25 mW / mK to less than 29.5 mW / mK. For convenience, the method according to this paragraph is referred to herein as Method 11F.

[0231] The present invention also provides a method for forming an extruded thermoplastic foam, the method comprising:

[0232] (i) providing a melt comprising or consisting essentially of polystyrene and a blowing agent, the blowing agent including each of Blowing Agent 1 through Blowing Agent 2, wherein the blowing agent is present in the melt in an amount from about 6 pph to less than 10 pph;

[0233] (ii) extruding the melt; and

[0234] (iii) foaming the melt to form a slurry having a density of about 25 kg / m 3 To less than 35.5kg / m 3 and an extruded polystyrene foam having an aged thermal conductivity of about 25 mW / mK to less than 29 mW / mK. For convenience, the method according to this paragraph is referred to herein as Method 11G.

[0235] The method of the present invention (including each of methods 1 to 11) can be formed with any PS resin, including general-purpose styrene resins, preferably having an MVR of 0.1 g / 10 min to 50 g / 10 min, more preferably 11 g / 10 min to 40 g / 10 min, and more preferably 10 g / 10 min to 30 g / 10 min.

[0236] These methods can be used, for example, Figure 1 The extrusion process is carried out using the general type of extrusion equipment disclosed in the present invention, which will be described in more detail below with reference to the examples. It should be understood that although Figure 1 Only a single feed point for introducing the blowing agent into the extrusion process is shown, but multiple feed points may be used to introduce the blowing agent. Furthermore, it should be understood that as used herein, the term "blowing agent" (including each of Blowing Agent 1 through Blowing Agent 2) includes not only the defined set of components introduced into the extruder when there is a single point of introduction, but also includes the aggregate combination of components that may be introduced into the extruder or other foaming equipment at multiple points.

[0237] Example

[0238] The following examples are provided for the purpose of illustrating the present invention but not to limit the scope of the present invention.

[0239] The embodiment uses essentially the Figure 1 . In particular, the apparatus includes a raw material feed hopper 10 for receiving polystyrene feed material 15 and any optional components (which may be added together with the polystyrene or optionally added elsewhere in the process, depending on the specific needs of the user). For the purposes of this embodiment of the present invention, the polystyrene feed is in the form of generic polystyrene pellets sold by Ineos under the trade name Styrolution 156F and has the following characteristics:

[0240] Characteristics, test conditions standard unit value Melt volume rate, 200℃ / 5kg ISO 1133 <![CDATA[cm 3 / 10min]]> 28 Vicat softening temperature VST / B / 50 (50N, 50℃ / h) ISO 306 ℃ 101 Melt temperature range ISO 294 ℃ 180-280

[0241] The feed material also includes a flame retardant sold under the trade name Apryos 5PB12HT, a nucleating agent (GRANIC 2281), and a processing aid (zinc stearate). The sum of the raw material feed stream 15 used to form the foam and introduced into the single screw extruder 20 is based on the following component concentrations:

[0242]

[0243]

[0244] The feed material 15 except whipping agent is loaded into hopper and is delivered to screw extruder 10 at a nominal rate of approximately 3.3 kilograms per hour, and is operated screw at a nominal 85rpm. Extruder 20 has a thermocouple (not shown) positioned at three points along its length and a pressure sensor (not shown) positioned at the discharge end 20A of extruder. Mixer section 30 is positioned at the discharge end 20A of extruder, for receiving whipping agent components via one or more metering pumps 40A and 40B, and those whipping agents are mixed into the polystyrene melt in the mixer section. Comprise sensor (not shown), for monitoring the temperature and pressure of mixer section 30. Mixer section 30 will be discharged into a pair of melt coolers 50 of series orientation with the melt of whipping agent, wherein temperature sensor (not shown) is positioned in each cooler to monitor melt temperature. Then melt is extruded through die head 60, which also has temperature sensor and pressure sensor (not shown) for monitoring the temperature and pressure at the die head. The die pressure was varied from 70 to 100 bar to minimize the density of each blowing agent tested, and the die temperature was maintained at 128° C. Leaving the die was a foamed sheet of polystyrene 70 which was carried away from the extrusion apparatus by a conveyor belt 80 .

[0245] Will Figure 1 The apparatus illustrated in FIG and described above was used in each of the experimental tests described in the following examples to form foam. After the foam was formed, density and aged thermal conductivity (also referred to as "aged λ") were measured. Aged λ values ​​were measured according to ISO 11561:199 (providing similar results to European Standard BS EN 13164:2012+A1:2015), modified as described below:

[0246] Day 0 – Squeeze the Bubble

[0247] Day 1 - Initial thermal conductivity of the blocks (skin, 120 mm x 120 mm, thickness 15 mm - 20 mm) was measured at 10°C + / - 2°C.

[0248] Day 4 - The block was cut into 6 mm thick slices (skin removed) to obtain one slice per extruded sample 23 mm wide and 120 mm long, and then at least 4 slices were stacked; the thermal conductivity of the stack was measured at 10°C + / - 2°C, and then the slices were separated and kept at about 23°C and 50% relative humidity.

[0249] Days 6 to 36 - Repeat the procedure of Day 4 every two or three days until about Day 28 is reached to obtain the aged thermal conductivity by Method A, which involves plotting the lambda value versus time and then calculating the aged thermal conductivity (lambda aged).

[0250] Δλ is the difference between the aged λ and the initial λ.

[0251] Comparative Examples C1 to C44—XPS Foam

[0252] In Comparative Examples C1 to C44, the above-described and Figure 1 Extruded polystyrene foams were produced using the equipment and materials exemplified in Tables C1-C44 below. All foams were made using the same raw materials, except that a different blowing agent was used in each case, as indicated in Tables C1-C44 below. In each case, the die pressure that minimized the foam density was determined and used to produce the foam.

[0253] After foam formation, density, initial thermal conductivity, and aged thermal conductivity (also referred to as "aged lambda") were measured as described above (unless indicated by the designation ND in Tables C1-C44, in which case the value was not determined). The results are reported in Tables C1-C44 below (where pph is parts by weight per hundred parts of polystyrene).

[0254] Tables C1-C44

[0255]

[0256]

[0257] As can be seen from Tables C1-C44 above, 44 different co-blowing agent combinations were used in the tests, where the combinations were based on two or more of the following:

[0258] HFC-134a(134a)

[0259] 1233zd(E)(1233zd)

[0260] Carbon dioxide (CO2)

[0261] Dimethyl ether (DME)

[0262] Ethanol (EtOH)

[0263] Isobutane (iC4)

[0264] Methyl formate (MF)

[0265] HFC-152a(152a)

[0266] Water(H2O)

[0267] The results of this experimental work generally show that, despite trying 44 different combinations of the above-mentioned components, it was not possible to obtain from these components in the amounts indicated a solution capable of achieving a mass fraction of less than 40 kg / m 3 , and even more preferably less than 39 kg / m 3 , and even more preferably less than 37 kg / m 3foamed polystyrene foams that achieve an aged lambda of less than 29.5 mW / mk while achieving a foam density of 40 kg / m3or less.

[0268] While several of these 44 foams achieved the required density, and while several of the foams achieved the required aged lambda, none of these experiments were able to achieve both of these highly desirable properties simultaneously.

[0269] Examples 1 to 12—XPS Foams from Blowing Agents Containing 134a, 1233zd(E), and Isobutane

[0270] A series of foam extrusion runs were conducted using the same equipment, the same operating standards, and the same feedstocks as described above in connection with the comparative examples, except that the blowing agents identified in Tables E1-E12 below were used and foams having the properties reported in Tables E1-E12 below were produced:

[0271] Tables E1-E12

[0272]

[0273] As can be seen from Tables E1-E12, Applicants have unexpectedly discovered that certain blowing agents can be formulated based on a combination of HFC- 134a, 1233zd(E), and isobutane (in both cases with and without DME or CO2) that are able to obtain thermoplastic foams having density and aged lambda values within the preferred requirements outlined herein. This is exemplified in Figure 2 Figure 2 Figure 2

[0274] Examples 13-32—XPS Foams from Blowing Agents Containing 134a, 1233zd(E), and Isobutane

[0275] As can be seen from Tables E1-E12, Applicants have unexpectedly discovered that certain blowing agents can be formulated based on a combination of HFC- 134a, 1233zd(E), and isobutane (in both cases with and without DME or CO2) that are able to obtain thermoplastic foams having density and aged lambda values within the preferred requirements outlined herein. This is exemplified in Figure 2 Figure 2 Figure 2 3 and even more preferably less than 39 kg / m3 3 and even more preferably less than 37 kg / m3 3 or less, and at the same time have a thermal conductivity of 29.5 or less. The other 44 comparative test results were not able to achieve foams having this highly desirable combination of important properties. This is an unexpected result.

[0274] Examples 13-32—XPS Foams from Blowing Agents Containing 134a, 1233zd(E), and Isobutane

[0275] A series of foam extrusion runs were conducted using the same equipment, the same operating standards, and the same feedstocks as described above in connection with the comparative examples, except that the blowing agents identified in Tables E1-E12 below were used and foams having the properties reported in Tables E1-E12 below were produced:

[0276] Table E13-E32

[0277]

[0278] As can be seen from Tables E13-E32, applicants have unexpectedly discovered that certain blowing agents can be formulated based on a combination of HFC-134a, 1233zd(E), and isobutane (both without and with DME and / or CO and / or water and / or ethanol) that are capable of obtaining thermoplastic foams having densities and aged lambda values ​​within the requirements outlined herein.

Claims

1. A method for forming extruded polystyrene foam, the method comprising: A thermoplastic polystyrene melt is provided comprising thermoplastic polystyrene and a blowing agent, the blowing agent comprising: about 10 wt% to about 30 wt% HCFO-1233zd(E); from about 35 wt. % to about 75 wt. % HFC-134a; from about 10 wt % to about 35 wt % isobutane; and optionally a fourth component comprising up to about 20% by weight of dimethyl ether and / or carbon dioxide and / or water and / or ethanol or a combination of two or more thereof, wherein the amount of components (i)-(iv) in the blowing agent is not less than about 95% by weight of all the blowing agent components in the formulation; and The thermoplastic material is foamed by a step comprising extruding the thermoplastic polystyrene melt to produce extruded polystyrene foam.

2. The method according to claim 1, wherein the foaming agent comprises: (i) from about 10 wt% to about 30 wt% HCFO-1233zd(E); (ii) from about 55 weight percent to about 75 weight percent HFC-134a; (iii) from about 20% to about 35% by weight of isobutane; and (iv) optionally a fourth component comprising up to about 20 weight percent dimethyl ether and / or carbon dioxide.

3. The method of claim 1 , wherein the blowing agent consists essentially of: i. from about 10 wt % to about 30 wt % HCFO-1233zd(E); ii. from about 35 wt% to about 65 wt% HFC-134a; and iii. from about 10 wt% to about 30 wt% isobutane.

4. The method of claim 1, wherein the extruded polystyrene foam has a density of about 37 kg / m3 or less and an aged thermal conductivity of 29.5 mW / mK or less.

5. The method of claim 1, wherein the extruded polystyrene foam has a density of about 36 kg / m3 or less and an aged thermal conductivity of 29 mW / mK or less.

6. A foaming agent, comprising: from about 10 wt% to about 35 wt% HCFO-1233zd(E); from about 35 wt. % to about 70 wt. % HFC-134a; from about 10 wt % to about 30 wt % isobutane; and optionally up to about 15 wt. % of a fourth component comprising dimethyl ether and / or carbon dioxide and / or water and / or ethanol or a combination of two or more thereof, The amount of components (a)-(d) in the blowing agent is not less than about 95% by weight of all the blowing agent components in the formulation.

7. The foaming agent according to claim 11, comprising: (i) from about 10 wt% to about 30 wt% HCFO-1233zd(E); (ii) from about 55 weight percent to about 75 weight percent HFC-134a; (iii) from about 15 weight percent to about 25 weight percent isobutane; and (iv) optionally up to about 10 wt. % of a fourth component comprising dimethyl ether and / or carbon dioxide and / or water and / or ethanol or a combination of two or more thereof, provided that components (i)-(iii) together constitute at least 90 wt. % of the blowing agent.

8. A thermoplastic foam comprising: (a) a thermoplastic polymer comprising a plurality of closed cells; and (b) a gaseous material contained in the plurality of closed cells, the gaseous material comprising: from about 10 wt% to about 35 wt% HCFO-1233zd(E); from about 35 wt. % to about 70 wt. % HFC-134a; from about 10 wt % to about 30 wt % isobutane; and optionally up to about 15 wt. % of a fourth component comprising dimethyl ether and / or carbon dioxide and / or water and / or ethanol or a combination of two or more thereof, wherein the amount of components (a)-(d) in the gaseous material is not less than about 85% by weight of all the components in the gaseous material.

9. The foam of claim 8, wherein the foam is an extruded polystyrene foam having a density of about 40 kg / m3 or less and an aged thermal conductivity of 30 mW / mK or less.

10. The foam of claim 8, wherein the foam is an extruded polystyrene foam having a density of about 35 kg / m3 or less and an aged thermal conductivity of 29.5 mW / mK or less.

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