High-efficiency impact modifier and polymer composition

Abstract

The present invention relates to core-shell impact modifier compositions, particularly high T impact modifiers with unique concentric morphology and / or high rubber loading and small particle size, and / or synthesized in a manner that requires low levels of surfactant. g Core, Low T g Inner shell and high T g This invention relates to compositions of core-shell impact modifiers having an outer shell. The incorporation of these impact modifiers into polymer compositions allows for a combination of properties not previously seen, i.e., high impact resistance while maintaining high gloss, or high impact resistance while maintaining low haze in the presence of hot water. These impact modifiers also allow for greater efficiency in their use, i.e., excellent impact resistance can be achieved at low loadings.

Description

Technical Field

[0001] The present invention relates to a core-shell type impact modifier composition, particularly a core-shell type impact modifier composition having a specific concentric morphology and / or having a high rubber filling amount and a small particle size and / or synthesized by a method requiring only a low level of surfactant, having a high T g core, a low T g inner shell, and a high T g external shell. By incorporating these impact modifiers into a polymer composition, it is possible to achieve the coexistence of properties not seen conventionally, that is, the coexistence of high impact resistance while maintaining high gloss, or the coexistence of high impact resistance while maintaining low haze in the presence of high-temperature water. Further, these impact modifiers enable excellent efficiency in their use, that is, it is possible to achieve excellent impact resistance with a low filling amount.

Background Art

[0002] Polymer products often require the coexistence of excellent impact resistance and excellent aesthetics, for example, high gloss for transparent or opaque articles, and strong resistance to fogging even in a high-temperature and high-humidity environment (generally referred to as "low water haze"). For many polymer materials, in order to improve the impact performance of the polymer composition, it is well established in the industry to use rubber-like particles having a low glass transition temperature (T g ). In particular, the use of spherical multilayer polymer particles composed of a core or inner shell of a rubbery low T g polymer and an outer shell of a high T g polymer having compatibility / affinity with the host matrix, so-called "core-shell type" impact modifiers, has been utilized for decades for toughening polymers such as PVC, PLA, PC, acrylic, epoxy, and polyester (US3843753, US3661994). For certain acrylic polymers such as polymethyl methacrylate (PMMA), a high T g core, a low T g rubbery inner shell, and a high Tg It has been demonstrated that using an outer shell is advantageous for achieving an optimal level of impact resistance performance (US443103, US4521568, US5270397).

[0003] Unfortunately, when core - shell impact - resistant modifier particles are used in a polymer composition, while the impact resistance performance is improved, there is a limit to the extent to which a brittle polymer matrix such as PMMA can be toughened. In US7294399B2, a high rubber filling amount is used in the core, and low T is used in the matrix. g It has been shown that by adding an alkyl acrylate comonomer, a significant improvement in impact resistance can be achieved in an acrylic formulation. However, using an alkyl acrylate copolymer in the above - mentioned matrix is harmful to the thermal properties of the composition such as the heat distortion temperature (HDT).

[0004] Also, unfortunately, when core - shell impact - resistant modifier particles are used in a polymer composition, although it is repetitive, while the impact resistance performance is improved, there is a possibility of harm to properties such as gloss, temperature haze (cloudiness that occurs in a transparent article when the temperature rises above the ambient temperature), and water haze resistance. In US2017 / 0298217A1 and WO2014 / 54543, it was shown that using a small particle size improves the resistance to water haze, but the improvement in impact properties is moderate and no improvement in water haze resistance was seen.

[0005] It is highly desirable to develop a core - shell impact - resistant modifier that enables excellent impact properties while maintaining very good aesthetics (high transparency or gloss), low - temperature haze, and high resistance to water haze in a brittle matrix such as PMMA. Similarly, it is also desirable to develop a very efficient impact - resistant modifier that can be used at a low filling amount but still extremely improves the impact resistance performance.

[0006] Surprisingly, it has been found that by developing core-shell type impact modifiers particles having a small particle size and a high rubber filling amount, excellent impact resistance performance can be achieved while maintaining excellent aesthetics. By developing highly concentric core-shell type particles, it has also been found that the impact resistance characteristics are improved, particularly in the case of small particle sizes. Finally, by restricting the use of surfactants in the synthesis of impact modifier particles, it has been found that excellent impact resistance can be achieved while maintaining a low water haze, particularly in the case of small particle sizes. By incorporating all three attributes into one particle, a very efficient core-shell type modifier for polymer compositions is realized. These compositions are expected to have strong value in applications such as automotive, construction and building, lighting, optics, electronics, transportation, electrical, signage and displays, household appliances, consumer goods, coatings, medical, cosmetics, UV personal care, packaging, and additive manufacturing.

Summary of the Invention

[0007] In a first aspect, the present invention is a latex composition comprising core-shell type particles, wherein the core-shell type particles are · a hard core polymer stage of 0.5 to 40 weight percent, preferably 1 to 20 weight percent, more preferably 2 to 15 weight percent, most preferably 5 to 10 weight percent, having a T higher than 0 °C g and · an internal polymer shell of 10 to 80 weight percent, preferably 55 to 80 weight percent, having a T lower than 0 °C g and · an external polymer shell of 5 to 50 weight percent, preferably 10 to 20 weight percent, having a T higher than 0 °C g and comprising the ratio of the emulsifier to the surface area of the core-shell type particles is 1.5×10 -4 g / m 2Regarding the above latex composition which is less than. The ratio of the emulsifier to the surface area of the above core-shell type particles is based on the above core-shell type particles in the state as synthesized and not further processed. Examples of further processing include, for example, washing, aggregation, and other similar post-polymerization treatments.

[0008] In a second aspect, the above hard core polymer stage of the above core-shell type particles has monomer units selected from the group consisting of at least 50 weight percent of methacrylate ester units, acrylate ester units, styrene-based monomer units, and mixtures thereof.

[0009] In a third aspect of the present invention, in the latex composition described in any of the preceding aspects, the above internal polymer shell has monomer units selected from the group consisting of at least 50 weight percent of alkyl acrylates, dienes, styrene-based monomers, and mixtures thereof.

[0010] In a fourth aspect of the present invention, the latex composition described in any of the preceding aspects has an external polymer shell having monomer units selected from the group consisting of at least 50 weight percent of methacrylate ester units, acrylate ester units, styrene-based monomer units, and mixtures thereof.

[0011] In a fifth aspect of the present invention, in the latex composition described in any of the preceding aspects, the radius of the entire core-shell type particles is 100 nm or less.

[0012] In a sixth aspect of the present invention, the radius of the core-shell type particles is 100 nm or less, and the above core-shell type particles are · 0.5 to 40 weight percent, preferably 1 to 20 weight percent, more preferably 2 to 15 weight percent, most preferably 5 to 10 weight percent of T higher than 0 °C g of the hard core polymer stage, and · 10 to 80 weight percent, preferably 55 to 80 weight percent of T lower than 0 °C gan inner polymer shell, and · 5 to 50 wt%, preferably 10 to 20 wt%, of T higher than 0 °C g an outer polymer shell of and consists of.

[0013] In a seventh aspect of the present invention, the polymer impact-modifying composition · 30 to 99 wt% of at least one polymer resin as a matrix, and · 1 to 70 wt% of the core-shell type particles according to any of the preceding aspects and contains.

[0014] In an eighth aspect of the present invention, the composition of the seventh aspect contains a polymer resin which is a thermoplastic resin.

[0015] In a ninth aspect of the present invention, the composition of aspect 7 or 8 contains the above thermoplastic resin which is an acrylic resin.

[0016] In a tenth aspect of the present invention, in the composition according to any of aspects 7 to 9, the concentration of the core-shell type particles in the above composition is 10 wt% to 60 wt%, preferably 20 wt% to 50 wt%.

[0017] In another aspect of the present invention, the polymer resin of the impact-modifying composition is a thermosetting resin.

[0018] In another aspect of the present invention, the impact-resistant modified composition described in the preceding aspect has the following characteristics, namely, an Izod impact strength exceeding 1.5 foot-pounds / inch; both an Izod impact strength exceeding 1.0 foot-pounds / inch and a tensile modulus exceeding 300,000 psi; a very low water haze, indicated by an Izod impact strength of at least 0.7 foot-pounds / inch and, for transparent samples, a delta haze of less than 1 or, for translucent or opaque samples, a ΔE of less than 2 (provided that these samples are those after being immersed in deionized water at 70°C for 24 hours and then conditioned at room temperature and 50% RH for more than 24 hours); both an Izod impact strength of at least 0.7 foot-pounds / inch and a 60° gloss after profile extrusion or coextrusion of a 250-micron-thick member or layer exceeding 30; or having any one of an Izod impact strength of at least 0.7 foot-pounds / inch and a room temperature haze of less than 2 after being immersed in deionized water at 70°C for 24 hours and then conditioned at room temperature and 50% RH for more than 24 hours.

[0019] In a further aspect of the present invention, in the impact-resistant modified composition described in any of the preceding aspects, the matrix and core-shell type particles are selected such that the difference in refractive index is within 0.08 units, preferably within 0.05 units, more preferably within 0.01 units.

[0020] In another aspect of the present invention, the Izod impact strength of the impact-resistant modified composition described in any of the preceding aspects is at least 0.7 foot-pounds / inch, and the transparency is at a high level indicated by a TLT exceeding 90%.

[0021] In another aspect of the present invention, the Izod impact strength of the impact-resistant modified composition described in any of the preceding aspects is at least 0.7 foot-pounds / inch, the water haze is less than 10%, and the TLT exceeds 90%.

[0022] Another aspect of the present invention relates to an article manufactured from the impact-resistant modified composition described in any of the preceding aspects.

[0023] An article according to the preceding aspect formed by melt processing, additive manufacturing techniques casting, infusion molding, wet compression molding, resin transfer molding, or pultrusion.

[0024] An article according to any of the preceding claims, which is a multi-layer article and at least one layer contains the impact-resistant modified composition.

[0025] An article according to any of the preceding claims, which is a fiber-reinforced article.

[0026] Building and construction articles, decking, handrails, plywood, fences, window and door profiles; automotive articles, exterior automotive trim, automotive interiors, automotive mirror housings, fenders; electronic articles, earphones, mobile phone cases, computer housings; energy-related articles, wind energy components, custom sheet articles, capstock; optical-related articles, visibility films for road signs; medical articles, intravenous injection fittings, luer, diagnostic device components; sports goods, shoe soles, tennis rackets, golf clubs, skis; infrastructure articles, bridge bearings, reinforcing bars; outdoor goods, snowmobile parts, RV parts, jet ski parts, coatings, medical instruments, cosmetics, UV personal care products, packaging materials, and additive manufacturing parts.

Mode for Carrying Out the Invention

[0027] The present invention relates to a core-shell type impact-resistant modifier composition and a polymer composition containing the core-shell type impact-resistant modifier.

[0028] All percentages used herein are weight percentages, and all molecular weights are weight average molecular weights measured by gel permeation unless otherwise specified. All cited references listed are incorporated herein by reference.

[0029] The description of the present invention is general and includes core - shell / acrylic polymer systems as model systems. Those skilled in the art will recognize that based on the following description and examples, equivalent results can be obtained using other polymer matrices.

[0030] Composition Core - shell impact modifier The impact modifier of the present invention is a multi - stage, sequentially produced polymer having a core - shell particle structure. The core - shell impact modifier has at least three layers (a hard core / an internal elastomeric shell layer / an external hard shell layer, known as "hard core, core - shell particles") or any number of layers beyond that, for example, a soft seed core surrounded by a hard core / an elastomeric intermediate shell layer / a second different elastomeric layer / and one or more high T g including an external shell layer. Other multi - layer similar structures are known in the art.

[0031] In a preferred embodiment, the presence of the hard core layer provides a desirable balance of good impact strength, high modulus of elasticity, and excellent UV resistance that cannot be achieved with core / shell modifiers having a soft core layer. As used herein, the core layer is defined as a polymer layer having at least two polymer layers on its outer side. The core layer does not necessarily have to be the innermost layer of the particle. The hard core layer (T g higher than 0 °C, preferably T g higher than 20 °C) is generally a single - composition polymer, but may include a small amount of low - T g seeds and the combination of the hard core layer formed thereon. For example, a 5% small rubber core seed dispersed in a hard inner layer is included in the present invention as a hard core layer as long as the combination behaves as a hard core high - T g layer. The hard core layer is T gIt can be selected from any combination of monomers that meet the requirements. The above hard core layer is preferably mainly composed of methacrylate units, acrylate units, styrene-based monomer units, or mixtures thereof. Examples of the methacrylate unit include, but are not limited to, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate, isobornyl methacrylate, phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate, and 2-methoxyethyl methacrylate. Examples of the acrylate unit include, but are not limited to, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate, isobornyl acrylate, phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate, and 2-methoxyethyl acrylate. The above acrylate unit is preferably selected from methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and octyl acrylate. Examples of the styrene-based monomer unit include styrene and derivatives of styrene such as α-methylstyrene and paramethylstyrene, but are not limited thereto. In one embodiment, the above hard core layer is all acrylic. In another embodiment, the above hard core layer is acrylic having less than 30% styrene-based monomer units.

[0032] At least one intermediate inner shell layer is an elastomer layer, and T g is lower than 0 °C, preferably lower than -20 °C. Preferred elastomers include polymers and copolymers of alkyl acrylates, dienes, styrene-based monomers, and mixtures thereof. The soft intermediate layer is preferably mainly composed of acrylate units. Acrylate units useful for forming the soft block include, but are not limited to, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate, isobornyl acrylate, phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate, and 2-methoxyethyl acrylate. The acrylate units are preferably selected from methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and octyl acrylate. Useful dienes include, but are not limited to, isoprene and butadiene. Useful styrene-based monomers include, but are not limited to, α-methylstyrene and para-methylstyrene. In a preferred embodiment, the acrylate units constitute more than 75% of the elastomer inner shell layer(s). The total amount of the elastomer layer(s) in the impact modifier is preferably 30 to 90 weight percent, more preferably 40 to 85 weight percent, and most preferably 55 to 80 weight percent based on the total weight of the impact modifier particles.

[0033] The outer hard shell layer has a T g higher than 0 °C, more preferably a T gis higher than 20°C and may preferably be composed of one or more shell layers selected from the above list of the hard core. The external shell layer may have the same or different composition as the hard core layer. As described in US7195820B2, in order to enhance the compatibility / affinity with the polymer matrix, a certain level of functional groups may be introduced into the shell. Hydrophilic monomers may be introduced into the shell to improve the coating rate of the shell or the antiblocking property. Examples of useful hydrophilic monomers include, but are not limited to, hydroxyalkyl (meth)acrylate, (meth)acrylic acid, (meth)acrylamide, (meth)acrylamine, polymerizable surfactants, and macromonomers containing hydrophilic moieties.

[0034] In one aspect of the present invention, the core-shell polymer is a three-stage composition, and the stages are a first-stage hard core layer in the range of 0.5 to 40 weight percent, preferably 1 to 20 weight percent, more preferably 2 to 15 weight percent, and even more preferably 5 to 10 weight percent; a second elastomeric inner shell stage of 10 to 80 weight percent, preferably 55 to 80 weight percent; and an external shell stage of 5 to 50 percent, preferably 10 to 20, provided that all percentages are based on the total weight of the three-stage polymer particles. The radius of the core-shell polymer particles is less than 200 nm, more preferably less than 100 nm. When the core-shell particles are added to the polymer composition, a small particle size is advantageous to maintain excellent aesthetic properties such as transparency or high gloss.

[0035] In another aspect of the present invention, the core-shell polymer is synthesized by a method that produces concentric circular particles similar to perfect bull's eyes. When utilized in a polymer composition, it has been found that this concentricity and circularity are advantageous for maximizing impact resistance performance.

[0036] The above core-shell polymer can be produced by any known technique for preparing a multi-stage, sequentially produced polymer, for example, by emulsion polymerization of a monomer mixture of the next stage in the presence of a previously formed polymer product. As used herein, the terms "sequentially emulsion polymerized" or "sequentially emulsion produced" refer to a polymer prepared in an aqueous dispersion or emulsion, in which, in the above polymer, monomers supplied previously and on the already formed latex prepared by polymerization of the stages polymerize on the already formed latex or in the presence of the above latex. In this form of polymerization, subsequent stages are joined to and tightly bound to the preceding stage.

[0037] In a preferred embodiment, the impact modifier is produced by sequential emulsion polymerization. As is known in the art, in this form of polymerization, an emulsifier is generally used to enable both the stabilization / transport of the supplied monomers to the growing core-shell type particles and the stabilization of the core-shell type particles themselves in an aqueous medium. An emulsifier is defined as any organic or inorganic molecule having both a hydrophobic component and a hydrophilic component in its structure. As the emulsifier, any one of known surfactants can be used, regardless of whether it is anionic, nonionic, or even cationic. In particular, the emulsifier is selected from anionic emulsifiers such as sodium or potassium salts of fatty acids, especially sodium laurate, sodium stearate, sodium palmitate, sodium oleate, sulfates-esters in which salts of sodium or potassium and esters of aliphatic alcohols coexist, especially sodium lauryl sulfate, sodium or potassium salts of sulfosuccinic acid esters, sodium or potassium salts of alkylaryl sulfonic acids, especially sodium dodecylbenzenesulfonate, and sodium or potassium salts of fatty acid monoglyceride monosulfonic acid esters, or from nonionic surfactants such as reaction products of ethylene oxide with alkylphenols or aliphatic alcohols, or multiple alkylphenols. If necessary, a mixture of such surfactants may be used.

[0038] In a more preferred embodiment, the emulsion synthesis of these particles is such that the ratio of the weight of the emulsifier to the surface area of the core-shell type particles is less than 1.5×10 -4 g / m 2 and preferably less than 9×10 -5 g / m 2 This ratio is the ratio present in the emulsion or after the recovery process (when no specific step for removing the emulsifier is utilized). Steps for removing the emulsifier include, but are not limited to, latex aggregation, latex dialysis, or washing of the already isolated particles. These methods can often improve the water haze performance beyond what is claimed in the present invention, but these methods introduce additional manufacturing steps and costs. Spray drying is a method known in the art for efficiently recovering core-shell type particles at low cost without an additional costly step for removing the emulsifier. The low emulsifier level of the particles recovered by spray drying is advantageous for maintaining a lower water haze when the core-shell type particles are used in a polymer composition.

[0039] In one embodiment of the present invention in which the impact modifier is produced by sequential emulsion polymerization, the aqueous reaction mixture obtained at the end of the final emulsion polymerization stage, which is composed of an aqueous emulsion of the polymer according to the present invention, is then processed to recover the polymer from the aqueous reaction mixture (often in powder form). Spray drying is a particularly preferred technique. Aggregation is an effective but more costly technique, in which the emulsion is contacted with a solution acidified with physiological saline (CaCl2 or AlCl3) or concentrated sulfuric acid, depending on the emulsifier used, so that the emulsion is subjected to an aggregation treatment. Then, the solid product resulting from the aggregation is separated by filtration. Then, the solid product is washed and dried to obtain a graft copolymer as a powder. It is also possible to recover the polymer contained in the emulsion by using drum drying, freeze drying, or other means known in the art. During any of these processes, additives such as talc, calcium carbonate, or silica may be used to assist in the processing of the powder. Hard particles may be used together with the core-shell type particles of the present invention to further improve the antiblocking properties and processing properties.

[0040] The impact modifier particles of the present invention may be intimately mixed with polymeric, organic, or inorganic dispersing aids, anti-caking agents, and / or other process aids, or other impact modifiers, as commonly done in the industry during the recovery process by spray drying or agglomeration. By this process, impact modifier composite particles are formed, in which the core-shell type impact modifier particles are intimately mixed with polymeric, organic, or inorganic additives, or process aids. The core-shell type impact modifier composite particles are produced by means known in the art, including but not limited to co-spray drying as a separate stream into a spray dryer; formulation as a dispersion of the core-shell type particles and a process aid, and spray drying of the mixture; co-agglomeration; co-freeze drying; coating of the dispersion or solution of the process aid onto the core-shell type particles, and subsequent drying; physical blending of the impact modifier and process aid powders (which enhances the homogeneity of the powder form and leads to a more homogeneous formulation in the matrix in the melt blend); and physical blending and subsequent mild melt blending of the impact modifier and process aid powders that enables softening and adhesion of the particles without complete melting, and may then be recovered in powder form.

[0041] The impact modifier particles are present in the final impact-modified polymer composition at a level of 5 to 80 weight percent, preferably 10 to 60 weight percent, more preferably 20 to 50 weight percent, based on the total composition.

[0042] Polymer composition The resin used as the matrix polymer in the composition of the present invention may be any thermoplastic or thermosetting resin. Particularly preferred thermoplastic plastics include, but are not limited to, acrylic polymers, styrenic polymers, polyolefins, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyvinyl chloride (PVC), polycarbonate (PC), thermoplastic polyurethane (PU), polylactic acid (PLA), thermoplastic fluoropolymers, polyamides, or mixtures thereof. Particularly preferred thermosetting polymers include, but are not limited to, epoxy resins, unsaturated polyester resins, vinyl ester resins, thermosetting polyurethanes, urea formaldehyde, melamine formaldehyde, UV curable, and thermosetting acrylic resins.

[0043] Styrenic polymers used herein include polystyrene, high impact polystyrene (HIPS), acrylonitrile-butadiene-styrene (ABS) copolymer, acrylonitrile-styrene-acrylate (ASA) copolymer, styrene-acrylonitrile (SAN) copolymer, methacrylate-acrylonitrile-butadiene-styrene (MABS) copolymer, styrene-butadiene copolymer (SB), styrene-butadiene-styrene block (SBS) copolymer and their partially or fully hydrogenated derivatives, styrene-isoprene copolymer, styrene-isoprene-styrene (SIS) block copolymer and their partially or fully hydrogenated derivatives, styrene-methyl methacrylate copolymer (S / MMA) such as styrene-methacrylate ester copolymers, and mixtures thereof, but are not limited thereto. A preferred styrenic polymer is ASA.

[0044] Examples of the acrylic polymers used in the present specification include, but are not limited to, homopolymers, copolymers, and terpolymers containing alkyl methacrylate. The alkyl methacrylate monomer is preferably methyl methacrylate, and this methyl methacrylate may constitute 51 to 100% by weight, preferably more than 60% by weight, more preferably more than 75% by weight, and most preferably more than 85% by weight of the monomer mixture. The remaining monomers used to form the polymer are selected from other acrylic esters, methacrylic esters, and / or other vinyl monomers. Other methacrylic esters, acrylic esters, and vinyl monomers useful in the monomer mixture include, but are not limited to, methyl acrylate, ethyl acrylate and ethyl methacrylate, butyl acrylate and butyl methacrylate, isooctyl methacrylate and isooctyl acrylate, lauryl acrylate and lauryl methacrylate, stearyl acrylate and stearyl methacrylate, isobornyl acrylate and isobornyl methacrylate, methoxy-ethyl acrylate and methoxy-ethyl methacrylate, 2-ethoxyethyl acrylate and 2-ethoxyethyl methacrylate, dimethylaminoethyl acrylate and dimethylaminoethyl methacrylate monomers, styrene and its derivatives. (Meth)acrylic acid alkyl such as (meth)acrylic acid and acrylic acid may be useful in the monomer mixture. A small amount of a polyfunctional monomer may be used as a crosslinking agent. Preferred acrylic polymers are copolymers of methyl methacrylate and 2 to 16% of one or more C1-4 acrylic esters.

[0045] The thermoplastic or thermosetting polymer used in the present invention can be produced by any means known in the art, including emulsion polymerization, bulk polymerization, solution polymerization, and suspension polymerization. In one embodiment, the weight average molecular weight of the polymer matrix, measured by gel permeation chromatography (GPC), is 50,000 to 5,000,000 g / mol, preferably 75,000 to 150,000 g / mol. The molecular weight distribution of the polymer matrix may be unimodal or multimodal with a polydispersity index exceeding 1.5.

[0046] In one embodiment, the composition of the polymer matrix and the core-shell type particles is selected such that the refractive index is within 0.008 units, preferably within 0.005 units, more preferably within 0.001 units, enabling a transparent formulation.

[0047] In another embodiment, a dye or pigment is added to the composition to enable a translucent or opaque material. The level of the pigment or dye in the composition is preferably 0.2 to 25 weight percent, preferably 0.5 to 20 weight percent, most preferably 1 to 5 weight percent, based on the total composition. By adding the dye or pigment, a transparent article with a haze level of less than 10 percent, preferably less than 3 percent; a translucent article with a haze level of 10 to 35 percent, preferably 15 to 25 percent; or an opaque article can be produced.

[0048] Useful dyes and pigments used in the present invention include nanocarbon materials such as graphite or carbon nanotubes, cadmium zinc sulfide, CI Pigment Yellow 35 (CAS Registry Number 8048-07-5, REACH Number 01-2119981639-18-0001), cadmium sulfoselenide orange, CI Pigment Orange 20 (CAS Registry Number 12656-57-4, REACH Number 01-2119981636-24-0001), cadmium sulfoselenide red (CI Pigment Red 108, CAS Registry Number 58339-34-7, REACH Number 01-2119981636-24-0001), carbon black (PBlk-7), TiO2 (PW-6), BaSO4 (PW-21 and PW-22), CaCO3 (PW-18), PbCO3, Pb(OH)2 (PW1), MACROLEX® Yellow 6G, MACROLEX® Yellow 3G, MACROLEX® Yellow G, MACROLEX® Yellow E2R, MACROLEX® Yellow RN, MACROLEX® Orange 3G, MACROLEX® Orange R, MACROLEX® Red E2G, MACROLEX® Red A, MACROLEX® Red EG, MACROLEX® Red G, MACROLEX® Red H, MACROLEX® Red B, MACROLEX® Red 5B, MACROLEX® Red Violet, MACROLEX® Violet 3R, MACROLEX® Violet B, MACROLEX® Violet 3B, MACROLEX® Blue 3R, MACROLEX® Blue RR, MACROLEX® Blue 2B, MACROLEX® Green 5B, MACROLEX® Green G, MACROLEX® Fluorescent Yel., and MACROLEX®, but are not limited thereto.

[0049] Other additives The above composition may optionally contain other impact modifiers (both core-shell and linear block copolymers), stabilizers, plasticizers, fillers, additives for improving scratch resistance and / or damage resistance, colorants, pigments, antioxidants, antistatic agents, surfactants, toners, additives for matching refractive indices, additives having specific photorefractive properties, light absorption properties, or light reflection properties, dispersion aids, poly(ethylene glycol), poly(propylene glycol), butyl lactate, and carboxylic acids such as lactic acid, oxalic acid, and acetic acid, radiation stabilizers, light-modifying additives such as polymeric or inorganic spherical particles with a particle size of 0.5 microns to 1,000 microns, etc., but not limited thereto, and may contain one or more common additives for polymer compositions in a normal effective amount. The amount of the additives contained in the above polymer composition may vary from about 0% to about 70% of the total weight of the polymer, inorganic mineral oxide, and additives. Generally, an amount of about 0.5% to about 45%, preferably about 5% to about 40% is contained. The above additives may be added to the composition before supplying the composition to the extruder, or may be added to the molten composition from the middle of the extruder.

[0050] Processing Process for synthesizing a core-shell type composite impact modifier The core / shell type polymer of the present invention is preferably synthesized by emulsion free radical polymerization. A general procedure for producing 4-stage core-shell type polymer particles is described. A person skilled in the art could modify this procedure to form other core-shell type particles useful as impact modifiers.

[0051] In the first stage (hard core layer), an emulsion is prepared containing 1 to 10 parts of water, 0.001 to 0.03 parts of an emulsifier, a part of a (meth)acrylic acid ester mixture, and at least one polyfunctional crosslinking agent per part by weight of the monomer to be polymerized. The reaction mixture thus formed is stirred and maintained at a temperature in the range of 45°C to 85°C, preferably in the range of 60 to 80°C. Next, a catalyst that generates 0.0001 to 0.005 parts of free radicals is added together with an equal amount of an activator compound that increases the radical flux, and the reaction mixture thus formed is maintained at a temperature between, for example, ambient temperature and 100°C for a time sufficient for the monomer to be substantially completely converted while stirring. Then, an alkyl acrylate monomer(s) and a grafting agent are added to the phase thus obtained, and simultaneously, 0.0001 to 0.005 parts of a catalyst that generates free radicals are added simultaneously a plurality of times until the target particle size is obtained.

[0052] In the second stage, the core has a T lower than 0°C gIt is grafted (inner shell) with a selected monomer that will form the polymer. To do this, an appropriate amount of the above monomer mixture, and, if appropriate, an additional amount of emulsifier and a radical catalyst within the ranges defined above are added to the reaction mixture obtained from the first stage to obtain a graft copolymer containing the desired content of graft chains. The mixture thus formed is maintained at a temperature higher than the above range with stirring until the graft monomer is substantially completely converted. As described above, any one of known surfactants can be used as the emulsifier, regardless of whether it is anionic, non-ionic, or even cationic. In particular, the emulsifier is a sodium or potassium salt of a fatty acid, especially sodium laurate, sodium stearate, sodium palmitate, sodium oleate, a sulfate-ester in which a salt of sodium or potassium and an ester of an aliphatic alcohol coexist, especially sodium lauryl sulfate, a sodium or potassium salt of a sulfosuccinic acid ester, a sodium or potassium salt of an alkylaryl sulfonic acid, especially sodium dodecylbenzenesulfonate, and a sodium or potassium salt of a fatty acid monoglyceride monosulfonic acid ester, etc., or a non-ionic surfactant such as a reaction product of ethylene oxide and an alkylphenol or an aliphatic alcohol, or a plurality of alkylphenols. If necessary, a mixture of such surfactants may be used. In one embodiment, the emulsion can be produced in a semi-continuous process, preferably at a reaction temperature of 60 to 90 °C, preferably 75 to 85 °C.

[0053] In the third stage, the elastomer shell has a T higher than 0 °C gis grafted (outer shell) with the selected monomers that will form the polymer. To do this, an appropriate amount of the monomer mixture, and, if appropriate, an additional amount of emulsifier and a radical catalyst within the ranges defined above are added to the reaction mixture obtained from the second stage in order to obtain a graft copolymer containing the desired content of graft chains, and the mixture thus formed is maintained at the temperature in the range of the second stage with stirring until the graft monomers are substantially completely converted. As described above, any one of the known surfactants can be used as the emulsifier, regardless of whether it is anionic, nonionic, or even cationic. In one embodiment, the emulsion can be produced in a semi - continuous process, preferably at a reaction temperature of 60 to 90 °C, preferably 75 to 85 °C.

[0054] In the fourth stage, the process of the third stage is repeated, as a result of which the shell thickness will increase, and the resulting latex can be isolated as a powder by spray drying.

[0055] Generally, preferred catalysts that can be used in all stages are compounds that generate free radicals under the temperature conditions selected for the polymerization. These compounds are, in particular, hydrogen peroxide, alkali metal persulfates, especially sodium or potassium persulfate, ammonium persulfate; peroxides such as percarbonate, peracetate, perborate, benzoyl peroxide or lauroyl peroxide, or peroxide compounds such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramethane hydroperoxide, tert-amyl or tert-butyl hydroperoxide. However, in the core stage, it is preferred to use a redox-type catalyst system formed by a combination of a non-ionic peroxide compound, such as the above-mentioned t-butyl hydroperoxide, and a reducing agent, especially an alkali metal sulfite, an alkali metal bisulfite, sodium formaldehyde sulfoxylate (NaHSO2·HCHO), ascorbic acid, glucose, especially water-soluble such catalyst systems, for example, t-butyl hydroperoxide / Bruggolite® FF7, or diisopropylbenzene hydroperoxide / sodium formaldehyde sulfoxylate. For the purpose of controlling the molecular weight of the above core and / or the molecular weight of the chains grafted onto the core in the polymerization mixture of one and / or the other of the above stages, a chain-limiting compound, especially a mercaptan such as dodecyl mercaptan, isobutyl mercaptan, octyl mercaptan, dimercapto dioxaoctane, or isooctyl mercaptopropionate, or for the purpose of controlling the ionic strength of the polymerization mixture, a compound such as phosphoric acid can also be added.

[0056] Process for incorporating core-shell type particles or core-shell type composite particles into a polymer composition The above polymer matrix and core-shell type particles or core-shell type composite particles can be blended in several different ways to provide an impact modifier that is well-dispersed in the composition. A preferred process in the case of a thermoplastic matrix involves a melt processing step. A particularly preferred method is to mix the thermoplastic matrix with the core-shell type particles in an extruder such as a twin-screw extruder. It is important to obtain good dispersion of the core-shell type particles.

[0057] Other means of blending the thermoplastic matrix with the core-shell type particles or core-shell type composite particles include: 1) blending the thermoplastic polymer matrix and the core-shell type particles in a colloidal state for both materials. This latex blend can be used as is, or the solid content can be recovered later by methods such as spray drying or agglomeration; 2) directly introducing the core-shell type particles into a liquid resin (using a liquid resin containing at least 25% level of matrix monomer before adding the core-shell type particles), and then polymerizing this (such as cell casting of MMA, polymerization of liquid composite resin, etc., or additive manufacturing techniques such as stereolithography (SLA)); 3) solvent casting of the particles and the dissolved matrix polymer; 4) powder blending followed by melt processing such as, but not limited to, extrusion molding, co-extrusion molding, injection molding, compression molding, or thermoforming; 5) powder blending followed by additive manufacturing techniques such as, but not limited to, selective laser sintering (SLS).

[0058] In the case of thermosetting resins, a preferred embodiment is to physically mix core-shell type particles or core-shell type composite particles into the liquid resin before complete curing occurs. Subsequently, the above thermosetting core-shell type particle mixture can be processed by casting or additive manufacturing techniques such as UV curing or SLA to form a thermosetting article or adhesive. The above thermosetting core-shell type particle mixture can also be processed by techniques such as infusion molding, resin transfer molding, or pull-out molding to form a fiber-reinforced composite structure. Other methods include, for example, powder blends for introducing the above core-shell type particles into a solid epoxy coating, or subsequent additive manufacturing techniques such as SLS, but are not limited thereto.

[0059] article In the case of thermoplastic matrices, articles and test flats are preferably formed by thermal processing. Useful thermal processing methods include, but are not limited to, injection molding, extrusion and co-extrusion, film extrusion, blow molding, lamination, extrusion lamination, rotational molding, infusion molding, pull-out molding, compression molding, and thermo-melt lamination molding. In the case of liquid thermoplastic resins, techniques such as casting, adhesive curing, or SLA can be utilized, while in the case of fiber-reinforced thermoplastic articles, processing techniques such as infusion molding, resin transfer molding, or pull-out molding can be utilized. Additive manufacturing techniques such as fused deposition modeling (FDM) and laser sintering can also be utilized.

[0060] In the case of thermosetting articles, processes such as casting, adhesive curing, infusion molding, resin transfer molding, wet compression molding, pull-out molding, spray-up and lay-up molding can be utilized to form articles and test flats. Additive manufacturing techniques such as SLA or SLS can also be utilized.

[0061] Other additives, as well as optional pigments and dyes, may be dry blended into the composition prior to heat processing into the final product. For some additives, such as pigments or dyes, masterbatches containing concentrates can also be used.

[0062] Multilayer articles are also contemplated by the present invention. The compositions of the present invention can be used in outer layers, inner layers, or any intermediate layer. The multilayer articles may be two-layer or multilayer and may include adhesive layers and / or tie layers.

[0063] Fiber-reinforced articles are also contemplated by the present invention. Useful fibers can include, but are not limited to, glass fibers, carbon fibers, or natural fibers.

[0064] Properties When the polymer compositions of the present invention are processed to form products or test specimens, a unique combination of impact resistance, aesthetics, and low water haze useful for several applications is obtained.

[0065] In a preferred embodiment, the article has high impact resistance. When measured by notched Izod (ASTM D256), the polymer composition achieves an impact resistance of greater than 1.5 foot-pounds / inch.

[0066] In another preferred embodiment, the article has a high level of impact resistance, but maintains a high modulus of elasticity because this very efficient impact modifier need only be used at a lower loading. When measured by notched Izod (ASTM D256), the polymer composition achieves an impact resistance of greater than 1 foot-pound / inch, yet still maintains a tensile modulus of elasticity of greater than 300,000 psi (ASTM D638).

[0067] In a preferred embodiment, the opaque / translucent article of the present invention has at least a moderate level of impact resistance (notched Izod in accordance with ASTM D256 exceeding 0.7 foot-pound / inch) and maintains a high gloss even after profile extrusion. The 60° gloss after profile extrusion or co-extrusion of a member or layer with a thickness of 250 microns exceeds 30 as measured by a Byk-Gardner micro gloss meter.

[0068] In a preferred embodiment, the opaque / translucent article of the present invention has at least a moderate level of impact resistance (notched Izod in accordance with ASTM D256 exceeding 0.7 foot-pound / inch), and the water haze of this material is also very low, less than 2.0, preferably less than 1.0, as indicated by the ΔE color value (measured in CIE L*a*b* with an X-Rite Color I7 spectrophotometer) of a test piece after exposure at 70 °C for 24 hours.

[0069] In a particularly preferred embodiment, the opaque / translucent article of the present invention has at least a moderate level of impact resistance (notched Izod in accordance with ASTM D256 exceeding 0.7 foot-pound / inch), a high level of gloss (the 60° gloss after profile extrusion or co-extrusion of a member or layer with a thickness of 250 microns exceeds 45 as measured by a Byk-Gardner micro gloss meter), and the water haze of this material is also very low, less than 2, as indicated by the ΔE color value (measured in CIE L*a*b* with an X-Rite Color I7 spectrophotometer) of a test piece after exposure at 70 °C for 24 hours.

[0070] In a preferred embodiment, the transparent article of the present invention has at least a moderate level of impact resistance (notched Izod in accordance with ASTM D256 exceeding 0.7 foot-pound / inch) and maintains a high transparency with a total light transmittance (TLT) exceeding 90% as measured by ASTM D1003.

[0071] In a preferred embodiment, the transparent article of the present invention has at least moderate impact resistance (notched Izod in accordance with ASTM D256 exceeding 0.7 foot-pound / inch), and the water haze of this material is also very low, as indicated by a change in haze of less than 5 units (measured in accordance with ASTM D1003) after immersion in deionized water at 70 °C for 24 hours and conditioning at room temperature, 50% RH for more than 24 hours.

[0072] In a particularly preferred embodiment, the transparent article of the present invention has at least a medium level of impact (notched Izod in accordance with ASTM D256 exceeding 0.7 foot-pound / inch) and high transparency (TLT measured by ASTM D1003 exceeding 90%), and the water haze of this material is also very low, as indicated by a change in haze of less than 2 units (measured in accordance with ASTM D1003) after immersion in deionized water at 70 °C for 24 hours and conditioning at room temperature, 50% RH for more than 24 hours.

[0073] Due to the preferred small particle size of the present invention, a low temperature haze of the polymer composition is also contemplated by the present invention. It is expected that the change in haze when the temperature rises from ambient temperature to 80 °C will be less than 20% (measured in accordance with ASTM D1003).

[0074] Use The composition of the present invention is useful for forming articles with high impact resistance, excellent aesthetics, and low water haze for applications including, but not limited to, architectural and construction articles (plywood, handrails, shuttering, fences, and window and door profiles); automotive applications (exterior trim, interiors, mirror housings, fenders, etc.); electronics (earphones, mobile phone cases, computer housings, etc.); energy applications (wind energy, etc.), particularly custom sheet applications as caps stock; optical applications (visibility films for road signs); medical (intravenous injection fittings such as luer, diagnostic device components); sports goods (shoe soles, tennis rackets, golf clubs, skis, etc.); infrastructure (bridges, reinforcing bars, etc.), outdoor goods (snowmobiles, RVs, jet skis, etc.), and applications manufactured by any form of additive manufacturing.

[0075] In this specification, embodiments have been described in a way that enables a clear and concise specification to be written, but it is intended and will be understood that the embodiments can be variously combined or divided without departing from the invention. For example, it will be understood that all the preferred features described herein are applicable to all aspects of the invention described herein.

Examples

[0076] Test methods All test specimens for physical and optical tests are injection molded with a thickness of 3.18 ± 0.05 mm and other dimensions as specified by ASTM standards. A.T g The glass transition temperature (T g ) is measured by DSC (differential scanning calorimetry) in accordance with Standard ISO 11357-2 (2013) and Standard ISO 11357-3 (2013) according to the following protocol. 1: Equilibrate at 20.00 °C 2: Cool to -50.00 °C at a rate of 10.00 °C / min 3: Hold at this temperature for 5.00 minutes 4: Heat to 250.00 °C at a rate of 20.00 °C / min 5: Hold at this temperature for 5.00 minutes 6: Cool to -50.00 °C at a rate of 10.00 °C / min 7: Hold at this temperature for 5.00 minutes 8: Heat to 250.00 °C at a rate of 20.00 °C / min B. Ratio of emulsifier to surface area The ratio of emulsifier to surface area is a calculated value. The volume average particle diameter and the average number of particles are measured by light scattering on the latex using a NICOMP 380 dynamic light scattering device. The polymer solids are measured by weighing an aluminum pan, adding the latex polymer and weighing again, and then evaporating the water in an oven to obtain the polymer solids as a mass percentage. The surface area of the particles is calculated based on the volume average radius measured by light scattering. The amount of emulsifier added to the latex is assumed to be present on the surface of all the particles. The polymer density is obtained by weighing the mass of the solid polymer and dividing by the volume. By using the average number of particles, the volume average particle diameter, the calculated surface area, the calculated density, and the polymer concentration, as well as the polymer density, the ratio of emulsifier to surface area can be calculated. C. Water haze For samples with a total light transmittance exceeding 50%, the water haze is the difference in haze measured using BYK HazeGard Plus under ASTM D1003 method between a sample that has been injection molded and conditioned at room temperature and humidity (23 °C, 50% relative humidity (RH)) and a sample that has been immersed in deionized water at 70 °C for 24 hours and then conditioned at room temperature and 50% relative humidity. Alternatively, for opaque samples, instead of the above (delta haze), the difference in the final color tone and the initial color tone (delta E) can be used. D. Gloss The surface gloss was measured at a measurement angle of 60 degrees using a BYK Spectro-Guide. E. Notched Izod impact strength is measured in accordance with ASTM D256 Abbreviations used in the examples: MMA = Methyl methacrylate EA = Ethyl acrylate BA = Butyl acrylate MA = Methyl acrylate Sty = Styrene ALMA = Allyl methacrylate GMAA = Methacrylic acid KDDBS = Potassium dodecylbenzenesulfonate

[0077] Example 1 This example illustrates the preparation of a polymer of a multi-stage, sequentially produced composition. The ratio of the three stages is 10 / / 75 / / 15, and the composition of the three stages is Stage 1: 79 / 20 / 1 MMA / BA / ALMA Stage 2: 82 / 17 / 1 BA / Sty / ALMA Stage 3: 100 MMA respectively. The feed monomers constituting Stage 1 were emulsified in deionized water using KDDBS. This emulsion was heated to 50 - 70 °C and initiated with a 1:1 weight ratio of tert-butyl hydroperoxide and bruggolite® FF7 reducing agent to obtain an appropriate polymerization rate. The temperature was raised to at least 80 °C, and after almost complete conversion, potassium carbonate was added to adjust the pH for Stages 2 and 3. The mixture of Stage 2 was gradually fed with a controlled amount of KDDBS to limit the formation of new particles and maintain the stability of the latex. Potassium persulfate was added simultaneously with the Stage 2 mixture to control the polymerization rate, residual salts, and pH level. After the addition, the latex was cured until the residual monomer was less than 1%. The monomer mixture of Stage 3 was gradually added with a limited amount of surfactant to control the particle growth. After the addition, the latex was cured until the amount of residual monomer was less than 0.1%. The polymer was isolated by coagulation, freeze-drying, or spray-drying.

[0078] Example 2 This polymer was prepared in the same manner as in Example 1, except that the stage ratios were different. The ratio of the three stages is 2 / / 75 / / 23, The composition of the stages was Stage 1: 8 / 90 / 2 MMA / Sty / ALMA Stage 2: 85 / 14 / 1.0 BA / Sty / ALMA Stage 3: 100 MMA It was as follows.

[0079] Example 3 This polymer was prepared in the same manner as in Example 1, except that the stage ratios were different. The ratios of the three stages were 6 / / 75 / / 19, and the composition of the stages was Stage 1: 8 / 90 / 2 MMA / Sty / ALMA Stage 2: 84 / 15 / 1.0 BA / Sty / ALMA Stage 3: 99 / 1 MMA / GMAA It was as follows.

[0080] Example 4 This polymer was prepared in the same manner as in Example 1, except that the stage ratios were different. The ratios of the three stages were 7 / / 75 / / 18, and the composition of the stages was Stage 1: 80 / 10 / 9.8 / 0.2 MMA / Sty / BA / ALMA Stage 2: 84 / 15 / 1 BA / Sty / ALMA Stage 3: 99 / 1 MMA / BA It was as follows.

[0081] Examples 5 and 6 (comparative) This example shows the preparation of a multi-stage, sequentially produced polymer of a given composition, using prior art methods, targeting radii of 80 nm and 150 nm respectively. The ratios of the three stages were 15 / / 65 / / 20, and the composition of the three stages was Stage 1: 74.8 / 25 / 0.2 MMA / EA / ALMA Stage 2: 83.5 / 15.5 / 1.0 BA / Sty / ALMA Stage 3: 95 / 5 MMA / EA It was 34% of the feed monomers constituting Stage 1 were emulsified in water using KDDBS as an emulsifier and potassium carbonate to control the pH, and polymerized at high temperature using potassium persulfate. Subsequently, the remaining portion of Stage 1 was added to the already formed polymer emulsion, and the amount of soap added was controlled to polymerize at high temperature using potassium persulfate while preventing the formation of a significant number of new particles. Next, the monomers of Stage 2 were added, and the amount of soap added was controlled to polymerize at high temperature using potassium persulfate while preventing the formation of a significant number of new particles. Then, again, the amount of soap added here was controlled to polymerize the monomers of Stage 3 at high temperature using potassium persulfate while preventing the formation of a significant number of new particles. The polymer was isolated by coagulation, freeze-drying, or spray-drying. The ratio of the three stages was 35 / / 45 / / 20 The composition of the three stages was Stage 1: 95.8 / 0.4 / 0.2 MMA / EA / ALMA Stage 2: 80 / 18 / 2.0 BA / Sty / ALMA Stage 3: 96 / 4 MMA / EA It is.

[0082] Examples 7 to 13 The polymers of Examples 1 to 6 were compounded in an extruder with the described amounts of acrylic copolymer matrix. TIFF0007708666000001.tif164170

[0083] Examples 7 to 13 were molded into 1 / 8-inch flat plates and 1 / 8-inch × 0.5-inch × 2.5-inch Izod bar specimens. The energy per notch length was measured on a ceast Izod tester in accordance with ASTM D256.

[0084] This table clearly shows the advantages of dispersing an optimized elastomer polymer in an acrylic copolymer matrix containing a low level of surfactant. Example 7 shows an impact resistance 2.67 times higher and a haze 8.1 units less than Example 11 after immersion at 70 °C for 24 hours, while optical properties such as TLT and haze are maintained. Example 7 also shows the advantages of the mixed initiator system during core-shell synthesis. Example 8 shows that an impact resistance of 2.65 foot-pounds / inch can be achieved with only a slight sacrifice of optical properties. Example 9 shows that a tensile modulus exceeding 300,000 psi can be achieved while the impact resistance is 1.19 foot-pounds / inch.

[0085] Examples 14 and 15 (profiled extrusion) Examples 14 and 15 are each composed of the materials of Examples 10 and 13 and are co-extruded onto PVC using profiled extrusion with a cap layer thickness of 200 - 250 microns. The thickness of the PVC was 1160 - 1270 microns. Next, the GVHIT impact strength of these composite materials is tested in accordance with ASTM D4226-00. TIFF0007708666000002.tif23170

[0086] The advantages of the materials such as Example 14 over earlier types of acrylic materials such as Example 15 are readily apparent. Example 15 does not meet the gloss requirements made possible by the present invention.

Claims

1. A latex composition comprising core-shell type particles, wherein the core-shell type particles comprise a. A rigid core polymer stage having from 0.5 to 40 weight percent of T higher than 0 °C ｇ and b. T lower than 0 °C when synthesized in the absence of a product comprising a rigid core polymer stage of 10 to 80 weight percent ｇ an internal polymer shell, showing c. T higher than 0 °C when synthesized in the absence of a product comprising a rigid core polymer stage and an internal polymer shell of 5 to 50 weight percent ｇ exhibited by an external polymer shell and comprising The ratio of the emulsifier to the surface area of the core-shell type particles in the emulsion is less than 9×10 －５ g / m ２ when based on the core-shell type particles in the as-synthesized state and not further processed, the hard core polymer stage comprises at least 50 weight percent of monomer units selected from the group consisting of methacrylic acid ester units, acrylic acid ester units, styrene-based monomer units, and mixtures thereof the internal polymer shell comprises at least 50 weight percent of monomer units selected from the group consisting of alkyl acrylate units, diene units, and mixtures thereof, and 14 to 17 weight percent of styrene-based monomer units the external polymer shell comprises at least 50 weight percent of monomer units selected from the group consisting of methacrylic acid ester units, acrylic acid ester units, and mixtures thereof The glass transition temperature (Tg) complies with Standard ISO 11357-2 and Standard ISO 11357-3, and the following protocol: 1: Equilibrate at 20.00 °C 2: Cool to -50.00 °C at a rate of 10.00 °C / min 3: Hold at this temperature for 5.00 minutes 4: Heat to 250.00 °C at a rate of 20.00 °C / min 5: Hold at this temperature for 5.00 minutes 6: Cool to -50.00 °C at a rate of 10.00 °C / min 7: Hold at this temperature for 5.00 minutes 8: Heat to 250.00 °C at a rate of 20.00 °C / min The latex composition measured by DSC (differential scanning calorimetry) according to

2. The latex composition according to claim 1, wherein the value obtained by dividing the volume average particle diameter of the core-shell type particles by 2 is 50 to 100 nm.

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