CN1865323B - Multilayer pellet and method for producing the same - Google Patents

Abstract

Multi-layer pellet and its preparation method The present invention discloses a multi-layer pellet, which comprises an inner core of a first material comprising a first thermoplastic resin and an outer sheath of a second material comprising a second thermoplastic resin, said An outer sheath surrounds said inner core, wherein (i) the first thermoplastic resin has a melt index of 200 g/10 min or greater as measured at a temperature of 230° C. and a load of 21.2 N, provided that the second thermoplastic resin is The melt index measured at a temperature of 230°C and a load of 21.2N is different from that of the first thermoplastic resin, or (ii) the first thermoplastic resin has a modified structure derived from a compound containing an unsaturated group. thermoplastic resin.

Description

Multi-layer pellets and preparation method thereof

technical field

The invention relates to a multi-layer thermoplastic resin pellet including an inner core and an outer sheath layer and a preparation method thereof.

In particular, the present invention relates to multilayer pellets having excellent fluidity and dispersibility in metals or other polymers, and also having excellent mechanical properties and paintability, as well as preparation of such pellets with good processability and production efficiency. Method for multi-layer pellets.

Furthermore, the present invention relates to multilayer pellets with excellent adhesion to metals or other polymers, and also excellent mechanical properties and paintability, as well as good processability and production with less odor emission Efficient method for preparing the multi-layer pellets

Background technique

Japanese Unexamined Patent Publication No. 2003-48991 discloses a multilayer pellet consisting of an outer sheath comprising component (A) and an inner core comprising component (B) and/or component (C), in

Component (A): crystalline polyolefin resin (A),

Component (B): an olefin copolymer composed of two or more olefins selected from the group consisting of ethylene, propylene or C _4-20 α-olefins, the ethylene, propylene and The C _4-20 α-olefin has a total number of carbon atoms of 6 or more and satisfies inequality (1):

[y/(x+y)]≥0.30(1)

wherein x is the content of ethylene (mol%), and y is the content (mol%) of C _4-20 α-olefins, component (C): (C-1) and/or (C-2)

(C-1): Copolymer composed of vinyl aromatic compound and conjugated diene compound

(C-2): a hydrogenation product of (C-1).

European Unexamined Patent Publication 1063070 A2 discloses a method for preparing multilayer pellets having an inner core-sheath structure in which the molding material forms an outer sheath surrounding another A peripheral covering of an inner core formed of a molding material, the method comprising:

(a): feeding the inner core material and the outer sheath material to a die assembly having a plurality of extruded forming parts arranged along a circumference,

(b): extruding a plurality of multi-layered strands from an extruded forming part by covering concentrically around the periphery of the core material with an outer sheath material, and

(c): Cutting the extruded multilayer strands to prepare multilayer pellets.

Japanese Unexamined Patent Publication No. 59-81121 discloses a method for preparing multilayer pellets, which comprises: comprising at least one compound selected from the group consisting of olefin-vinyl alcohol copolymers, ionically crosslinked olefin copolymers and linear polypolymers. Melt extrusion of resins in amide resins and melts mainly composed of olefin-based resins to form strands consisting of the inner core of the former melt and the outer sheath of the latter melt, the strands are cooled, and then cut The strands form pellets.

Contents of the invention

Summary of the invention

An object of the present invention is to provide a thermoplastic resin material having good mechanical properties and good paintability, in particular, to provide a thermoplastic resin material which has excellent mechanical properties and paintability, and also has excellent molding properties. fluidity, and has excellent dispersibility with metal or other thermoplastic resins, and provides a thermoplastic resin material that has excellent mechanical properties and paintability, and also has excellent adhesion with metal or other thermoplastic resins .

Another object of the present invention is to provide a method for preparing these thermoplastic resin materials.

In a first aspect, the present invention provides a multilayer pellet comprising an inner core of a first material comprising a first thermoplastic resin and an outer sheath of a second material comprising a second thermoplastic resin, said outer sheath Surrounding said inner core, wherein the first thermoplastic resin has a melt index of 200 g/10 min or greater measured at a temperature of 230°C and a load of 21.2 N, provided that the second thermoplastic resin is at a temperature of 230°C and a load of 21.2 The melt index measured under the load of N is different from the melt index of the first thermoplastic resin.

In a preferred embodiment, the weight ratio of the outer sheath to the inner core is 50/50 to 1/99.

In another preferred embodiment, the first thermoplastic resin is a modified polyolefin resin prepared by melt-kneading a polyolefin resin as a raw material, an unsaturated group-containing compound, and an organic peroxide.

In yet another preferred embodiment, the first thermoplastic resin is a modified thermoplastic resin prepared by melt-kneading a thermoplastic resin as a raw material, a compound containing both an unsaturated group and a polar group, and an organic peroxide; And in a more specific embodiment, the thermoplastic resin as a raw material is a polyolefin resin.

In a second aspect, the present invention provides a method of preparing a multilayer pellet comprising an inner core of a first material comprising a first thermoplastic resin and an outer core of a second material comprising a second thermoplastic resin. a sheath, said outer sheath surrounding said inner core, wherein the first thermoplastic resin has a melt index of 200 g/10 min or greater as measured at a temperature of 230°C and a load of 21.2 N, provided that the second thermoplastic resin The melt index of the resin measured at a temperature of 230°C and a load of 21.2N is different from the melt index of the first thermoplastic resin, the method comprising:

Provided is a multilayer extruder having a die having a first extrusion section through which a first material is extruded as an inner core and a second material through which a second material is extruded as an outer sheath. an extrusion, a second extrusion disposed to surround the first extrusion; a first feeder for feeding a first material to the first extrusion; and a first feeder for feeding a second material to the first extrusion Second feeder for two extrusion sections,

feeding the first material from the first feeder to the first extrusion section,

feeding the second material from the second feeder to the second extrusion section,

extruding the first material through the first extrusion section and extruding the second material through the second extrusion section to cover the first material with the second material to form a multilayer extrudate, and

The multilayer extrudate is cut to predetermined lengths to form multilayer pellets.

In a preferred embodiment, the first thermoplastic resin is formed in a first feeder by melt-kneading a thermoplastic resin as a raw material, a compound containing both an unsaturated group and a polar group, and an organic peroxide of.

In another preferred embodiment, said die is a right angle die.

In a third aspect, the present invention provides a multilayer pellet comprising an inner core of a first material comprising a first thermoplastic resin and an outer sheath of a second material comprising a second thermoplastic resin, said outer sheath Surrounding said inner core, wherein the first thermoplastic resin is a modified thermoplastic resin having a structure derived from a compound containing an unsaturated group.

In a preferred embodiment, the modified thermoplastic resin has a structure derived from a compound containing both unsaturated groups and polar groups.

In another preferred embodiment, the weight ratio of the outer sheath to the inner core is 50/50 to 1/99.

In yet another preferred embodiment, the first thermoplastic resin is a modified thermoplastic resin prepared by melt-kneading a thermoplastic resin as a raw material, a compound containing both an unsaturated group and a polar group, and an organic peroxide.

In yet another preferred embodiment, the first thermoplastic resin is prepared by adding 100 parts by weight of thermoplastic resin as a raw material, 0.01 parts by weight or more of a compound containing both unsaturated groups and polar groups, and 0.001 to 20 parts by weight A modified thermoplastic resin prepared by melt-kneading an organic peroxide.

In yet another preferred embodiment, the first thermoplastic resin has a melt index of less than 200 g/10 min measured at a temperature of 230° C. and a load of 21.2 N.

In a fourth aspect, the present invention provides a method of preparing a multilayer pellet comprising an inner core of a first material comprising a first thermoplastic resin and an outer core of a second material comprising a second thermoplastic resin. a sheath, said outer sheath surrounding said inner core, wherein the first thermoplastic resin is a modified thermoplastic resin having a structure derived from a compound containing an unsaturated group, the method comprising:

Provided is a multilayer extruder having a die having a first extrusion section through which a first material is extruded as an inner core and a second material through which a second material is extruded as an outer sheath. an extrusion, a second extrusion disposed to surround the first extrusion; a first feeder for feeding a first material to the first extrusion; and a first feeder for feeding a second material to the first extrusion Second feeder for two extrusion sections,

feeding the first material from the first feeder to the first extrusion section,

feeding the second material from the second feeder to the second extrusion section,

extruding the first material through the first extrusion section and extruding the second material through the second extrusion section to cover the first material with the second material to form a multilayer extrudate, and

The multilayer extrudate is cut to predetermined lengths to form multilayer pellets.

In a preferred embodiment, the first thermoplastic resin is formed in a first feeder by melt-kneading a thermoplastic resin as a raw material, a compound containing both an unsaturated group and a polar group, and an organic peroxide of.

In another preferred embodiment, said die is a right angle die.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

First, the first and second aspects of the present invention are explained below.

The multilayer pellets of the present invention comprise an inner core of a first material comprising a first thermoplastic resin and an outer sheath of a second material comprising a second thermoplastic resin, said outer sheath surrounding said inner core, wherein the second A thermoplastic resin having a melt index of 200 g/10 min or greater as measured at a temperature of 230° C. and a load of 21.2 N. Here, the melt index of the second thermoplastic resin measured at a temperature of 230° C. and a load of 21.2 N was different from that of the first thermoplastic resin.

Considering the fluidity and melt tension of the material in the process of melting and molding the multilayer pellets, it is preferable that the weight ratio of the outer sheath to the inner core is 50/50 to 1/99, and more preferably 30/70 to 1/99.

The first thermoplastic resin included in the first material constituting the inner core of the multilayer pellet has a melt index of 200 g/10 min or more, and preferably 200 to Within the range of 20000g/10min.

It is preferable that the first thermoplastic resin is a graft-modified thermoplastic resin prepared by melt-kneading a thermoplastic resin as a raw material, a compound containing both an unsaturated group and a polar group, and an organic peroxide; and more preferably the first thermoplastic resin The thermoplastic resin is a modified polyolefin resin prepared by using a polyolefin resin as a "thermoplastic resin as a raw material".

It is preferable that the first thermoplastic resin is a modified thermoplastic resin prepared by melt-kneading a thermoplastic resin as a raw material, a compound containing both an unsaturated group and a polar group, and an organic peroxide; and more preferably by using a polyolefin The resin is a modified polyolefin prepared as a "thermoplastic resin as a raw material".

As for the second thermoplastic resin included in the second material constituting the outer sheath layer, a thermoplastic resin is selected that is different from the second thermoplastic resin included in the second material constituting the inner core in terms of melt index measured at a temperature of 230° C. and a load of 21.2 N. A first thermoplastic resin in a material. The melt index of the second thermoplastic resin is preferably lower than 200 g/10 min, more preferably in the range of 0.1 to 150 g/10 min, measured at a temperature of 230° C. and a load of 21.2 N.

Examples of the first thermoplastic resin for the inner core and the second thermoplastic resin for the outer sheath include: polyolefin resins; styrenic resins such as polystyrene, high-impact polystyrene (that is, containing a small amount of its butadiene cross-linked polystyrene), and ABS resins; acrylic resins, such as polymethyl methacrylate; polyester resins, such as polyethylene terephthalate and polybutylene terephthalate Glycol esters; polycarbonate resins, such as polycarbonate; polyamide resins, such as polyamide 66, polyamide 6, and polyamide 46; polyacetal resins, such as polyoxymethylene copolymers and polyoxymethylene homopolymers; engineering plastics , such as polyethersulfone, polyetherimide, thermoplastic polyimide, polyetherketone, polyetheretherketone, and polyphenylene sulfide; cellulose derivatives, such as cellulose acetate, cellulose acetate butyrate, and ethyl cellulose thermoplastic elastomers, such as thermoplastic polyurethane elastomers, thermoplastic styrene-butadiene elastomers, thermoplastic polyester elastomers, thermoplastic vinyl chloride elastomers, and thermoplastic polyamide elastomers; fluororesins; and their modified products.

The first thermoplastic resin for the inner core is preferably a polyolefin resin (e.g., ethylene polymer resin, propylene polymer resin, butene polymer resin, ethylene, aromatic vinyl compound (e.g., styrene) and conjugated di ethylene (eg, 1,3-butadiene) copolymers); and more preferably ethylene polymer resins and propylene polymer resins; and still more preferably propylene polymer resins.

The first thermoplastic resin may be a single thermoplastic resin or a mixture of two or more thermoplastic resins. Similarly, the second thermoplastic resin may be a single thermoplastic resin or a mixture of two or more thermoplastic resins.

"Ethylene polymer resin" as used herein is a polymerization product of monomers mainly composed of ethylene. Examples thereof include ethylene homopolymers, copolymers consisting of 51 to 99.99% by weight of structural units derived from ethylene and 0.01 to 49% by weight of structural units derived from one or more monomers copolymerizable with ethylene, and their mixture.

Examples of the "monomer copolymerizable with ethylene" include propylene, α-olefins having 4 to 20 carbon atoms, acrylates, methacrylates and vinyl acetate. Examples of "α-olefins having 4 to 20 carbon atoms" include 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and vinylcyclohexane. An example of "acrylate" is methyl acrylate, and an example of "methacrylate" is methyl methacrylate.

Examples of "copolymers of ethylene and copolymers of ethylene and monomers that can be copolymerized with ethylene" include ethylene-propylene copolymers, ethylene-α-olefin copolymers, ethylene-methyl methacrylate copolymers, and ethylene-acetic acid vinyl ester copolymer. Examples of "ethylene-α-olefin copolymer" include ethylene-1-butene copolymer, ethylene-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer and ethylene-1- 1-decene copolymer.

The "propylene polymer resin" as used herein is a polymerization product of monomers mainly composed of propylene. Examples thereof include propylene homopolymers; propylene-ethylene random copolymers consisting of 51 to 99.99% by weight of structural units derived from propylene and 0.01 to 49% by weight of structural units derived from ethylene; 51 to 99.99% by weight of structural units derived from Random copolymers of propylene-α-olefins consisting of structural units of propylene and 0.01 to 49% by weight of structural units derived from one or more α-olefins containing 4 to 20 carbon atoms; included as part of a propylene homopolymer Propylene-ethylene block copolymer of the first segment and the second segment of the propylene-ethylene random copolymer part; including the first segment of the propylene homopolymer part and the propylene-α-olefin random Propylene-α-olefin block copolymers of the second segment of the copolymer portion, wherein the α-olefin is an α-olefin having 4 to 20 carbon atoms; and mixtures thereof.

Examples of "α-olefins having 4 to 20 carbon atoms" used in the production of propylene-α-olefin random copolymers and propylene-α-olefin block copolymers include 1-butene, 1-pentene, 1 -hexene, 1-octene, 1-decene and vinylcyclohexane. 1-butene is preferred.

Preferable examples of the propylene-α-olefin random copolymer include propylene-1-butene random copolymer. Preferable examples of the propylene-α-olefin block copolymers include propylene-1-butene block copolymers.

Propylene-ethylene block copolymers and propylene-alpha-olefin block copolymers are generally prepared by using a process comprising step (i) and step (ii), step (i) producing what will be the first segment Propylene homopolymer, step (ii) prepares the copolymer which will be the second segment in the presence of the propylene homopolymer prepared in step (i).

Preferable examples of the first thermoplastic resin included in the first material constituting the inner core include modified thermoplastic resins prepared by melt-kneading thermoplastic resins as raw materials, unsaturated group-containing compounds, and organic peroxides. Specifically, a modified polyolefin resin prepared by using a polyolefin resin as the "thermoplastic resin as a raw material" is preferable.

Among the unsaturated group-containing compounds used to prepare the modified thermoplastic resin, the unsaturated group may preferably be a carbon-carbon double bond-containing group or a carbon-carbon triple bond-containing group. Particular preference is given to groups containing carbon-carbon double bonds.

It is preferable that the compound containing an unsaturated group also contains a polar group. Examples of such polar groups include carboxyl, alkoxycarbonyl, allyloxy, amino, amido, imide, nitrile, epoxy, hydroxyl, isocyanate; derived from carboxylic acid, amide, Functional groups of acid azide, acid halide, acid anhydride, oxazoline, etc.; and functional groups derived from carboxylate, amide salt, salt of acid azide, salt of acid halide, etc.

Examples of unsaturated group-containing compounds include unsaturated carboxylic acids, unsaturated carboxylic acid derivatives, unsaturated epoxy compounds, unsaturated alcohols, unsaturated amines, and unsaturated isocyanates.

More specific examples of compounds containing unsaturated groups include:

(1) Maleic acid, maleic anhydride, fumaric acid, maleimide, maleic hydrazide, methyl norbornene diacid anhydride, dichloromaleic anhydride, maleamide, itaconic acid, itaconic acid Conic anhydride, glycidyl (meth)acrylate, 2-hydroxyethyl methacrylate and allyl glycidyl ether,

(2) The reaction product of maleic anhydride and diamine, such as the compound with the structure of following formula:

wherein R represents an aliphatic group or an aromatic group,

(3) Natural oils such as soybean oil, tung oil, castor oil, linseed oil, hempseed oil, cottonseed oil, sesame oil, rapeseed oil, peanut oil, camellia oil, olive oil, coconut oil and sardine oil,

(4) Epoxidized natural oil

(5) Unsaturated carboxylic acids such as acrylic acid, crotonic acid, crotonic acid, vinyl acetic acid, methacrylic acid, pentenoic acid, angelic acid, tiglic acid, 2-pentenoic acid, 3-pentenoic acid, α -Ethylacrylic acid, β-methylcrotonic acid, 4-pentenoic acid, 2-hexenoic acid, 2-methyl-2-pentenoic acid, 3-methyl-2-pentenoic acid, α-ethyl Crotonic acid, 2,2-dimethyl-3-butenoic acid, 2-heptenoic acid, 2-octenoic acid, 4-decenoic acid, 9-undecenoic acid, 10-undecenoic acid , 4-dodecenoic acid, 5-dodecenoic acid, 4-tetradecenoic acid, 9-tetradecenoic acid, 9-hexadecenoic acid, 2-octadecenoic acid, 9 -octadecenoic acid, eicosenoic acid, docosenoic acid, erucic acid, tetradecenoic acid, mycolipidic acid, 2,4-hexadienoic acid, diallyl acetic acid, zygomatic acid ( geranium acid), 2,4-decadienoic acid, 2,4-dodecadienoic acid, 9,12-hexadecadienoic acid, 9,12-octadecadienoic acid, hexadecatrienoic acid enoic acid, eicosadienoic acid, eicosatrienoic acid, eicosatetraenoic acid, ricinoleic acid, erucic acid, oleic acid, eicosadienoic acid, erucic acid, docosadienoic acid (docosadienoic acid), docosatrienoic acid, docosatetraenoic acid, docosapentaenoic acid, hexadecenoic acid, hexadecadienoic acid, octacosenoic acid (octacosenoic acid) and tetracontenoic acid (tetracontenoic acid),

(6) ester compounds, amide compounds or anhydrides of the above-mentioned unsaturated carboxylic acids,

(7) Allyl alcohol, crotyl alcohol, methyl vinyl carbinol, allyl carbinol, methacryl carbinol, 4-penten-1-ol, 10-undecen-1-ol, propargyl alcohol , 1,4-pentadien-3-ol, 1,4-hexadien-3-ol, 3,5-hexadien-2-ol and 2,4-hexadien-1-ol,

(8) Unsaturated alcohols, such as 3-butene-1,2-diol, 2,5-dimethyl-3-hexene-2,5-diol, 1,5-hexadiene-3, 4-diol and 2,6-octadiene-4,5-diol,

(9) unsaturated amines obtained by substituting _-NH2 groups for the OH groups of the above unsaturated alcohols,

(10) Addition products of maleic anhydride of phenols with oligomers of butadiene, isoprene, etc. (for example, polymers having a number average molecular weight of from about 500 to about 10,000),

(11) Addition products of maleic anhydride of phenol and high polymers of butadiene, isoprene, etc. (for example, polymers with a number average molecular weight of 10,000 or more),

(12) Obtained by introducing amino groups, carboxyl groups, hydroxyl groups, epoxy groups, etc. into oligomers of butadiene, isoprene, etc. (for example, polymers having a number average molecular weight of about 500 to about 10000) substance,

(13) Substances obtained by introducing amino groups, carboxyl groups, hydroxyl groups, epoxy groups, etc. into high polymers of butadiene, isoprene, etc. (for example, polymers with a number average molecular weight of 10000 or more) ,

(14) Allyl isocyanate.

The compound containing unsaturated groups is preferably selected from the group consisting of: maleic anhydride, maleic acid, fumaric acid, itaconic anhydride, itaconic acid, glycidyl (meth)acrylate and 2-hydroxyethyl methacrylate.

Compounds containing unsaturated groups may contain two or more unsaturated groups of the same or different types. When the compound containing an unsaturated group also contains a polar group, it may contain two or more polar groups of the same or different types.

Considering the graft ratio of the unsaturated group-containing compound to the thermoplastic resin and the paintability of the resin product prepared from the multilayer pellets of the present invention, based on 100 parts by weight of the thermoplastic resin as a raw material, the unsaturated group-containing compound The usage amount of is typically 0.01 to 30 parts by weight, and preferably 0.1 to 20 parts by weight.

Considering the grafting ratio of the unsaturated group-containing compound to the thermoplastic resin and avoiding the decomposition of the thermoplastic resin as a raw material, it is preferable that the organic peroxide used together with the unsaturated group-containing compound is decomposed at 50 to 210°C An organic peroxide whose half-life becomes 1 minute over the temperature range. Preferred is an organic peroxide that has an effect of extracting protons from the decomposed thermoplastic resin as a raw material and generating radicals. The active oxygen content of the organic peroxide is preferably 1 to 11%, and more preferably 2 to 20%. In addition, the amount of active oxygen is defined by the following formula:

Amount of active oxygen (%)=[(number of peroxide bonds in one organic peroxide molecule)×16)]×(purity of organic peroxide (%))/(molecular weight of organic peroxide)

Wherein the peroxide bond refers to an -O-O- bond.

Examples of organic peroxides whose half-life becomes 1 minute in the decomposition temperature range of 50 to 210°C include diacyl peroxides, dialkyl peroxides, peroxyketals, alkyl peresters, and percarbonic acids Salt. Preferred are dialkyl peroxides, diacyl peroxides, percarbonates and alkyl peresters.

Specific examples of organic peroxides include: bis(hexadecyl) peroxydicarbonate, (di-3-methoxybutyl) peroxydicarbonate, (di-2-ethylhexyl) peroxydicarbonate ester, bis(4-tert-butylcyclohexyl) peroxydicarbonate, diisopropyl peroxydicarbonate, tert-butyl peroxyisopropyl carbonate, dimyristyl peroxycarbonate, 1,1,3,3 -Tetramethylbutyl neodecanoate, α-cumylperoxyneodecanoate, tert-butyl peroxyneodecanoate, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2 -bis(4,4-di-tert-butylperoxycyclohexyl)propane, 1,1-bis(tert-butylperoxy)cyclododecane, tert-hexylperoxyisopropyl monocarbonate, tert-butyl Peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxylaurate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, peracetic acid tert-butyl ester, 2,2-bis(tert-butylperoxy)butene, tert-butyl peroxybenzoate, n-butyl-4,4-bis(tert-butylperoxy)valerate, di-tert- Butyl peroxyisophthalate, dicumyl peroxide, α,α'-bis(tert-butylperoxy-m-isopropyl)benzene, 2,5-dimethyl-2,5- Di-(tert-butylperoxy)hexane, 1,3-bis(tert-butylperoxyisopropyl)benzene, tert-butylcumyl peroxide, di-tert-butyl peroxide, p-hydroperoxide Menthane and 2,5-Dimethyl-2,5-di-(tert-butylperoxy)hexyne-3.

The organic peroxide is used in an amount of 0.001 to 20 parts by weight, and preferably 0.003 to 10 parts by weight, based on 100 parts by weight of the thermoplastic resin as a raw material.

When a thermoplastic resin as a raw material is melt-kneaded in the presence of an unsaturated group-containing compound and an organic peroxide to prepare a modified thermoplastic resin, aromatic vinyl compounds such as styrene and divinylbenzene may be added , so that the modified thermoplastic resin has a structure derived from aromatic vinyl compounds. The aromatic vinyl compound is used in an amount of at most 15 parts by weight, and preferably at most 7 parts by weight, based on 100 parts by weight of the thermoplastic resin as a raw material.

The outer sheath and/or inner core of the pellets of the present invention may contain additives such as antioxidants, neutralizers, lubricants, antistatic agents, nucleating agents, UV inhibitors, flame retardants, fillers, plasticizers , foaming agent, foaming aid, dispersant, anti-adhesive agent, anti-halation agent, antibacterial agent, cross-linking agent, cross-linking aid, organic porous powder and pigment.

The first material constituting the core includes a first thermoplastic resin. The content of the first thermoplastic resin in the first material is typically 50 to 100% by weight, and preferably 70 to 100% by weight.

The second material constituting the sheath layer includes a second thermoplastic resin. The content of the second thermoplastic resin in the second material is typically 50 to 100% by weight, and preferably 70 to 100% by weight.

The multi-layer pellets of the present invention have an inner core and one or more outer sheath layers formed outside the inner core. When two or more outer sheath layers are present, at least one outer sheath layer must satisfy the above requirements, and one or more layers that do not satisfy these requirements may exist.

The multilayer pellets of the invention typically have a length of 1 to 30 mm and a thickness of 0.5 to 20 mm, preferably 2 to 8 mm.

The multilayer pellets of the present invention can be prepared using the method disclosed in European Unexamined Patent Publication 1063070 A2.

In particular, they can be prepared by a method comprising:

Provided is a multilayer extruder having a die having a first extrusion section through which a first material is extruded as an inner core and a second material through which a second material is extruded as an outer sheath. an extrusion, a second extrusion disposed to surround the first extrusion; a first feeder for feeding a first material to the first extrusion; and a first feeder for feeding a second material to the first extrusion Second feeder for two extrusion sections,

feeding the first material from the first feeder to the first extrusion section,

feeding the second material from the second feeder to the second extrusion section,

extruding the first material through the first extrusion section and extruding the second material through the second extrusion section to cover the first material with the second material to form a multilayer extrudate, and

The multilayer extrudate is cut to predetermined lengths to form multilayer pellets.

There is no particular limitation on the method of feeding the first material for the inner core to the first extrusion part of the die and the method of feeding the second material for the outer sheath to the second extrusion part of the die . As for the first feeder for feeding the first material to the first extrusion section of the die and the second feeder for feeding the second material to the second extrusion section of the die, it can be Conventional extruders are used, such as FR extruders (feeder ruders), cold feed extruders and twin-screw conical extruders. The extruder can be either a single-screw extruder or a twin-screw extruder.

The method described above is typically applied to prepare bilayer pellets consisting of an inner core and an outer sheath. However, when it is desired to prepare multi-layered pellets having two or more outer sheath layers or multi-layered pellets further comprising an outer sheath layer and a plurality of layers other than the outer sheath layer made of the above-mentioned special material When used, such multilayer pellets can be prepared using a multilayer extruder configured to form an additional layer or layers by extrusion.

The number of feeders used is determined by the number of layers to be included in the desired multilayer pellet. When forming a two-layer structure consisting of an inner core and an outer sheath layer, two or more feeders are used. In the case of a three-layer structure consisting of an inner core, an outer sheath layer and another layer, three or more feeders are used. Preference is given to using so-called right-angle dies as said dies. A "square die" as used herein is a die of such a style that the local flow direction is turned so as to cross the direction of extrusion of the material. A preferred example of a right-angle die having such a structure is the one disclosed in detail in European Unexamined Publication 1063070 A2.

The multilayer extrudates (multilayer strands) can be cooled by suitable methods such as water cooling and air cooling. For cutting the multilayer extrudate to predetermined lengths, cutters conventionally used for the preparation of resin pellets can be used.

Next, the third and fourth aspects of the present invention are explained below.

The multilayer pellets of the present invention comprise an inner core of a first material comprising a first thermoplastic resin and an outer sheath of a second material comprising a second thermoplastic resin, said outer sheath surrounding said inner core, the first A thermoplastic resin is a modified thermoplastic resin having a structure derived from an unsaturated group-containing compound.

In view of preventing the deterioration of the adhesion of the multi-layered pellets to metal or other thermoplastic resins or preventing the generation of odor from the multi-layered pellets, it is preferable that the weight ratio of the outer sheath to the inner core is 50/50 to 1/99 , and more preferably from 30/70 to 1/99.

In the multilayer pellet of the present invention, the first thermoplastic resin included in the first material constituting the inner core is a modified thermoplastic resin having a structure derived from a compound containing an unsaturated group, and preferably has a structure derived from A modified thermoplastic resin with a compound structure containing both unsaturated groups and polar groups.

The first thermoplastic resin, which is a modified thermoplastic resin having a structure derived from an unsaturated group-containing compound, is prepared by treating a thermoplastic resin as a raw material with an unsaturated group-containing compound and has such a structure A thermoplastic resin in which a structure derived from an unsaturated group-containing compound has been introduced as a part of the molecular structure into a thermoplastic resin as a raw material.

The melt index of the first thermoplastic resin is preferably less than 200 g/10 min, and more preferably in the range of 0.1 to 150 g/10 min, measured at a temperature of 230° C. and a load of 21.2 N.

On the other hand, the second thermoplastic resin included in the second material constituting the sheath layer preferably has a melt index of less than 200 g/10 min, and more preferably in the range of 0.1 to 150 g, as measured at a temperature of 230° C. and a load of 21.2 N. /10min range.

It is preferable that the first thermoplastic resin is a modified polyolefin resin prepared by melt-kneading a thermoplastic resin as a raw material, an unsaturated group-containing compound, and an organic peroxide; and more preferably it is obtained by using 100 parts by weight of A modified polyolefin resin prepared by melt-kneading a thermoplastic resin, 0.01 parts by weight or more of an unsaturated group-containing compound, and 0.001 to 20 parts by weight of an organic peroxide.

A modified thermoplastic resin prepared by using a compound also having a polar group as the compound having an unsaturated group is more preferable.

Examples of the thermoplastic resin used as a raw material in the preparation of the modified thermoplastic resin used to form the inner core and the second thermoplastic resin used to form the outer sheath layer include: polyolefin resins; styrene resins such as polystyrene, impact-resistant polyester Styrene (i.e., polystyrene containing a small amount of its cross-linked product with polybutadiene), and ABS resins; acrylic resins, such as polymethyl methacrylate; polyester resins, such as polyethylene terephthalate Glycol esters and polybutylene terephthalate; polycarbonate resins such as polycarbonate; polyamide resins such as polyamide 66, polyamide 6 and polyamide 46; polyacetal resins such as polyoxymethylene copolymer and polyoxymethylene homopolymers; engineering plastics such as polyethersulfone, polyetherimide, thermoplastic polyimide, polyetherketone, polyetheretherketone, and polyphenylene sulfide; cellulose derivatives such as cellulose acetate , cellulose acetate butyrate and ethyl cellulose; thermoplastic elastomers such as thermoplastic polyurethane elastomers, thermoplastic styrene-butadiene elastomers, thermoplastic polyester elastomers, thermoplastic vinyl chloride elastomers and thermoplastic polyamide elastomers; Fluorine resins; and their modified products.

The thermoplastic resin used as a raw material in the preparation of the modified thermoplastic resin for forming the inner core and the second thermoplastic resin for forming the outer sheath layer are preferably polyolefin resins (for example, ethylene polymer resin, propylene polymer resin, butene polymer resin, Polymer resins, hydrogen adducts of copolymers of ethylene, aromatic vinyl compounds (e.g., styrene) and conjugated dienes (e.g., 1,3-butadiene); and more preferably ethylene polymers resins and propylene polymer resins; and still more preferably propylene polymer resins.

The first thermoplastic resin may be a single thermoplastic resin or a mixture of two or more thermoplastic resins. Similarly, the second thermoplastic resin may be a single thermoplastic resin or a mixture of two or more thermoplastic resins.

"Ethylene polymer resin" as used herein is a polymerization product of monomers mainly composed of ethylene. Examples thereof include ethylene homopolymers, copolymers consisting of 51 to 99.99% by weight of structural units derived from ethylene and 0.01 to 49% by weight of structural units derived from one or more monomers copolymerizable with ethylene, and their mixture.

Examples of the "monomer copolymerizable with ethylene" include propylene, α-olefins having 4 to 20 carbon atoms, acrylates, methacrylates and vinyl acetate. Examples of "α-olefins having 4 to 20 carbon atoms" include 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and vinylcyclohexane. An example of "acrylate" is methyl acrylate, and an example of "methacrylate" is methyl methacrylate.

Examples of "copolymers of ethylene and copolymers of ethylene and monomers that can be copolymerized with ethylene" include ethylene-propylene copolymers, ethylene-α-olefin copolymers, ethylene-methyl methacrylate copolymers, and ethylene-acetic acid vinyl ester copolymer. Examples of "ethylene-α-olefin copolymer" include ethylene-1-butene copolymer, ethylene-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer and ethylene-1- 1-decene copolymer.

The "propylene polymer resin" as used herein is a polymerization product of monomers mainly composed of propylene. Examples thereof include propylene homopolymers; propylene-ethylene random copolymers consisting of 51 to 99.99% by weight of structural units derived from propylene and 0.01 to 49% by weight of structural units derived from ethylene; 51 to 99.99% by weight of structural units derived from Random copolymers of propylene-α-olefins consisting of structural units of propylene and 0.01 to 49% by weight of structural units derived from one or more α-olefins containing 4 to 20 carbon atoms; included as part of a propylene homopolymer Propylene-ethylene block copolymer of the first segment and the second segment of the propylene-ethylene random copolymer part; including the first segment of the propylene homopolymer part and the propylene-α-olefin random Propylene-α-olefin block copolymers of the second segment of the copolymer portion, wherein the α-olefin is an α-olefin having 4 to 20 carbon atoms; and mixtures thereof.

Examples of "α-olefins having 4 to 20 carbon atoms" used in the production of propylene-α-olefin random copolymers and propylene-α-olefin block copolymers include 1-butene, 1-pentene, 1 -hexene, 1-octene, 1-decene and vinylcyclohexane. 1-butene is preferred.

Preferable examples of the propylene-α-olefin random copolymer include propylene-1-butene random copolymer. Preferable examples of the propylene-α-olefin block copolymers include propylene-1-butene block copolymers.

Propylene-ethylene block copolymers and propylene-alpha-olefin block copolymers are generally prepared by using a process comprising step (i) and step (ii), step (i) producing what will be the first segment Propylene homopolymer, step (ii) prepares the copolymer which will be the second segment in the presence of the propylene homopolymer prepared in step (i).

In the unsaturated group-containing compound used to prepare the modified thermoplastic resin for forming the inner core of the multilayer pellet of the present invention, the unsaturated group may preferably be a group containing a carbon-carbon double bond or containing A group with a carbon-carbon triple bond. Particular preference is given to groups containing carbon-carbon double bonds.

It is preferable that the compound containing an unsaturated group also contains a polar group. Examples of such polar groups include carboxyl, alkoxycarbonyl, allyloxy, amino, amido, imide, nitrile, epoxy, hydroxyl, isocyanate; derived from carboxylic acid, amide, Functional groups of acid azide, acid halide, acid anhydride, oxazoline, etc.; and functional groups derived from carboxylate, amide salt, salt of acid azide, salt of acid halide, etc.

Examples of unsaturated group-containing compounds include unsaturated carboxylic acids, unsaturated carboxylic acid derivatives, unsaturated epoxy compounds, unsaturated alcohols, unsaturated amines, and unsaturated isocyanates.

More specific examples of compounds containing unsaturated groups include:

(1) Maleic acid, maleic anhydride, fumaric acid, maleimide, maleic hydrazide, methyl norbornene diacid anhydride, dichloromaleic anhydride, maleamide, itaconic acid, itaconic acid Conic anhydride, glycidyl (meth)acrylate, 2-hydroxyethyl methacrylate and allyl glycidyl ether,

(2) The reaction product of maleic anhydride and diamine, such as the compound with the structure of following formula:

wherein R represents an aliphatic group or an aromatic group,

(3) Natural oils such as soybean oil, tung oil, castor oil, linseed oil, hempseed oil, cottonseed oil, sesame oil, rapeseed oil, peanut oil, camellia oil, olive oil, coconut oil and sardine oil,

(4) Epoxidized natural oil

(5) Unsaturated carboxylic acids such as acrylic acid, crotonic acid, crotonic acid, vinyl acetic acid, methacrylic acid, pentenoic acid, angelic acid, tiglic acid, 2-pentenoic acid, 3-pentenoic acid, α -Ethylacrylic acid, β-methylcrotonic acid, 4-pentenoic acid, 2-hexenoic acid, 2-methyl-2-pentenoic acid, 3-methyl-2-pentenoic acid, α-ethyl Crotonic acid, 2,2-dimethyl-3-butenoic acid, 2-heptenoic acid, 2-octenoic acid, 4-decenoic acid, 9-undecenoic acid, 10-undecenoic acid , 4-dodecenoic acid, 5-dodecenoic acid, 4-tetradecenoic acid, 9-tetradecenoic acid, 9-hexadecenoic acid, 2-octadecenoic acid, 9 -octadecenoic acid, eicosenoic acid, docosenoic acid, erucic acid, tetradecenoic acid, mycolipidic acid, 2,4-hexadienoic acid, diallyl acetic acid, zygomatic acid, 2,4-Decadienoic acid, 2,4-Dodecadienoic acid, 9,12-Hexadecadienoic acid, 9,12-Octadecadienoic acid, Hexadecatrienoic acid, Di Decadedienoic Acid, Eicosatrienoic Acid, Eicosatetraenoic Acid, Ricinoleic Acid, Jaruic Acid, Oleic Acid, Eicospentaenoic Acid, Erucic Acid, Docosadienoic Acid, Behenic Acid Carbatrienoic acid, docosatetraenoic acid, docosapentaenoic acid, hexadecenoic acid, hexadecadienoic acid, octacosenoic acid and eicosenoic acid,

(6) ester compounds, amide compounds or anhydrides of the above-mentioned unsaturated carboxylic acids,

(7) Allyl alcohol, crotyl alcohol, methyl vinyl carbinol, allyl carbinol, methacryl carbinol, 4-penten-1-ol, 10-undecen-1-ol, propargyl alcohol , 1,4-pentadien-3-ol, 1,4-hexadien-3-ol, 3,5-hexadien-2-ol and 2,4-hexadien-1-ol,

(8) Unsaturated alcohols, such as 3-butene-1,2-diol, 2,5-dimethyl-3-hexene-2,5-diol, 1,5-hexadiene-3, 4-diol and 2,6-octadiene-4,5-diol,

(9) unsaturated amines obtained by substituting _-NH2 groups for the OH groups of the above unsaturated alcohols,

(10) Addition products of maleic anhydride of phenols with oligomers of butadiene, isoprene, etc. (for example, polymers having a number average molecular weight of from about 500 to about 10,000),

(11) Addition products of maleic anhydride of phenol and high polymers of butadiene, isoprene, etc. (for example, polymers with a number average molecular weight of 10,000 or more),

(12) Obtained by introducing amino groups, carboxyl groups, hydroxyl groups, epoxy groups, etc. into oligomers of butadiene, isoprene, etc. (for example, polymers having a number average molecular weight of about 500 to about 10000) substance,

(13) Substances obtained by introducing amino groups, carboxyl groups, hydroxyl groups, epoxy groups, etc. into high polymers of butadiene, isoprene, etc. (for example, polymers with a number average molecular weight of 10000 or more) ,

(14) Allyl isocyanate.

The compound containing unsaturated groups is preferably selected from the group consisting of: maleic anhydride, maleic acid, fumaric acid, itaconic anhydride, itaconic acid, glycidyl (meth)acrylate and 2-hydroxyethyl methacrylate.

Compounds containing unsaturated groups may contain two or more unsaturated groups of the same or different types. When the compound containing an unsaturated group also contains a polar group, it may contain two or more polar groups of the same or different types.

Considering the graft ratio of the unsaturated group-containing compound to the thermoplastic resin and the paintability of the resin product prepared from the multilayer pellets of the present invention, based on 100 parts by weight of the thermoplastic resin as a raw material, the unsaturated group-containing compound The usage amount of is typically 0.01 to 30 parts by weight, and preferably 0.1 to 20 parts by weight.

Considering the grafting ratio of the unsaturated group-containing compound to the thermoplastic resin and avoiding the decomposition of the thermoplastic resin as a raw material, it is preferable that the organic peroxide used together with the unsaturated group-containing compound is decomposed at 50 to 210°C An organic peroxide whose half-life becomes 1 minute over the temperature range. Preferred is an organic peroxide that has an effect of extracting protons from the decomposed thermoplastic resin as a raw material and generating radicals. The active oxygen content of the organic peroxide is preferably 1 to 11%, and more preferably 2 to 20%. In addition, the amount of active oxygen is defined by the following formula:

Amount of active oxygen (%)=[(number of peroxide bonds in one organic peroxide molecule)×16)]×(purity of organic peroxide (%))/(molecular weight of organic peroxide)

Wherein the peroxide bond refers to an -O-O- bond.

Examples of organic peroxides whose half-life becomes 1 minute in the decomposition temperature range of 50 to 210°C include diacyl peroxides, dialkyl peroxides, peroxyketals, alkyl peresters, and percarbonic acids Salt. Preferred are dialkyl peroxides, diacyl peroxides, percarbonates and alkyl peresters.

Specific examples of organic peroxides include: bis(hexadecyl) peroxydicarbonate, (di-3-methoxybutyl) peroxydicarbonate, (di-2-ethylhexyl) peroxydicarbonate ester, bis(4-tert-butylcyclohexyl) peroxydicarbonate, diisopropyl peroxydicarbonate, tert-butyl peroxyisopropyl carbonate, dimyristyl peroxycarbonate, 1,1,3,3 -Tetramethylbutyl neodecanoate, α-cumylperoxyneodecanoate, tert-butyl peroxyneodecanoate, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2 -bis(4,4-di-tert-butylperoxycyclohexyl)propane, 1,1-bis(tert-butylperoxy)cyclododecane, tert-hexylperoxyisopropyl monocarbonate, tert-butyl Peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxylaurate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, peracetic acid tert-butyl ester, 2,2-bis(tert-butylperoxy)butene, tert-butyl peroxybenzoate, n-butyl-4,4-bis(tert-butylperoxy)valerate, di-tert- Butyl peroxyisophthalate, dicumyl peroxide, α,α'-bis(tert-butylperoxy-m-isopropyl)benzene, 2,5-dimethyl-2,5- Di-(tert-butylperoxy)hexane, 1,3-bis(tert-butylperoxyisopropyl)benzene, tert-butylcumyl peroxide, di-tert-butyl peroxide, p-hydroperoxide Menthane and 2,5-Dimethyl-2,5-di-(tert-butylperoxy)hexyne-3.

The organic peroxide is used in an amount of 0.001 to 20 parts by weight, and preferably 0.003 to 10 parts by weight, based on 100 parts by weight of the thermoplastic resin as a raw material.

When a thermoplastic resin as a raw material is melt-kneaded in the presence of an unsaturated group-containing compound and an organic peroxide to prepare a modified thermoplastic resin, aromatic vinyl compounds such as styrene and divinylbenzene may be added , so that the modified thermoplastic resin has a structure derived from aromatic vinyl compounds. The aromatic vinyl compound is used in an amount of at most 15 parts by weight, and preferably at most 7 parts by weight, based on 100 parts by weight of the thermoplastic resin as a raw material.

The outer sheath and/or inner core of the pellets of the present invention may contain additives such as antioxidants, neutralizers, lubricants, antistatic agents, nucleating agents, UV inhibitors, flame retardants, fillers, plasticizers , foaming agent, foaming aid, dispersant, anti-adhesive agent, anti-halation agent, antibacterial agent, cross-linking agent, cross-linking aid, organic porous powder and pigment.

The first material constituting the core includes a first thermoplastic resin. The content of the first thermoplastic resin in the first material is typically 50 to 100% by weight, and preferably 70 to 100% by weight.

The second material constituting the sheath layer includes a second thermoplastic resin. The content of the second thermoplastic resin in the second material is typically 50 to 100% by weight, and preferably 70 to 100% by weight.

The multi-layer pellets of the present invention have an inner core and one or more outer sheath layers formed outside the inner core. When two or more outer sheath layers are present, at least one outer sheath layer must satisfy the above requirements, and one or more layers that do not satisfy these requirements may exist.

Typically, the multilayer pellets of the invention have a length of 1 to 30 mm and a thickness of 0.5 to 20 mm, preferably 2 to 8 mm.

The multilayer pellets of the present invention can be prepared using the method disclosed in European pre-examined patent publication 1063070.

In particular, they can be prepared by a method comprising:

Provided is a multilayer extruder having a die having a first extrusion section through which a first material is extruded as an inner core and a second material through which a second material is extruded as an outer sheath. an extrusion, a second extrusion disposed to surround the first extrusion; a first feeder for feeding a first material to the first extrusion; and a first feeder for feeding a second material to the first extrusion Second feeder for two extrusion sections,

feeding the first material from the first feeder to the first extrusion section,

feeding the second material from the second feeder to the second extrusion section,

extruding the first material through the first extrusion section and extruding the second material through the second extrusion section to cover the first material with the second material to form a multilayer extrudate, and

The multilayer extrudate is cut to predetermined lengths to form multilayer pellets.

There is no particular limitation on the method of feeding the first material for the inner core to the first extrusion part of the die and the method of feeding the second material for the outer sheath to the second extrusion part of the die . As for the first feeder for feeding the first material to the first extrusion section of the die and the second feeder for feeding the second material to the second extrusion section of the die, it can be Conventional extruders are used, such as FR extruders, cold-feed extruders and twin-screw conical extruders. The extruder can be either a single-screw extruder or a twin-screw extruder.

The method described above is typically applied to prepare bilayer pellets consisting of an inner core and an outer sheath. However, when it is desired to prepare multi-layered pellets having two or more outer sheath layers or multi-layered pellets further comprising an outer sheath layer and a plurality of layers other than the outer sheath layer made of the above-mentioned special material When used, such multilayer pellets can be prepared using a multilayer extruder configured to form an additional layer or layers by extrusion.

The number of feeders used is determined by the number of layers to be included in the desired multilayer pellet. When forming a two-layer structure consisting of an inner core and an outer sheath layer, two or more feeders are used. In the case of a three-layer structure consisting of an inner core, an outer sheath layer and another layer, three or more feeders are used. Preference is given to using so-called right-angle dies as said dies. A "square die" as used herein is a die of such a style that the local flow direction is turned so as to cross the direction of extrusion of the material. A preferred example of a right-angle die having such a structure is the one disclosed in detail in European Unexamined Publication 1063070 A2.

The multilayer extrudates (multilayer strands) can be cooled by suitable methods such as water cooling and air cooling. For cutting the multilayer extrudate to predetermined lengths, cutters conventionally used for the preparation of resin pellets can be used.

The multilayer pellets of the present invention can be used as raw materials for forming various resin products. For example, it can be used as a raw material for the following: parts of vehicles, parts of electrical or electronic instruments, electric wires, wire coverings, construction materials, agricultural, marine or horticultural supplies, chemical industry supplies, civil engineering materials, furniture, stationery, Daily necessities, clothing, containers and packaging materials, toys, leisure items and medical supplies.

Specific examples of vehicle parts include: automotive interior parts, such as dashboards, doors and pillars, and automotive exterior parts, such as bumpers. Examples of wires include plastic cables and insulated wires.

Detailed ways

Example

The present invention is further described below with reference to Examples and Comparison, but the present invention is not limited to these Examples.

<Physical property measurement>

1. Melt index (MI, unit: g/10min)

Measured at 230°C under a load of 21.2N in accordance with JIS K7210.

2. Grafting ratio (unit: wt%)

Take the measurement as follows:

(1) A solution was prepared by dissolving 1.0 g of a graft-modified resin sample in 10 ml of xylene,

(2) Reprecipitate the graft-modified resin by adding the solution dropwise to 300 ml of methanol under stirring,

(3) collect the grafted modified resin of precipitation,

(4) The grafted modified resin collected by vacuum drying (80 DEG C, 8 hours)

(5) hot pressing the dry graft modified resin to form a film with a thickness of 100 μm, and

(6) The infrared absorption spectrum of the film was measured, and the grafting ratio was determined based on the absorption around 1730 cm ⁻¹ .

Example 1

To 100 parts by weight of propylene homopolymer (trade name: Noblene HA100E, manufactured by SumitomoChemical Co., Ltd., MI=300g/10min), 5 parts by weight of maleic anhydride, 0.50 parts by weight of peroxydicarbonic acid were added Two (hexadecyl) ester (active oxygen=2.8%, the decomposition temperature=99 ℃ that provides 1min half-life), 0.15 parts by weight of 1,3-bis(tert-butylperoxyisopropyl)benzene (active oxygen= 9.3%, providing 1min half-life decomposition temperature = 183 ° C), 0.05 parts by weight of calcium stearate (neutralizing agent) and 0.3 parts by weight of tetrakis [methylene-3-(3,5-di-tert-butyl -4-hydroxyphenyl)propionate]methane (antioxidant) and mixed well at room temperature to obtain a blend.

The blend was fed into a twin-screw extruder (PCM46, manufactured by IKEGAI Ltd.; screw design: diameter = 46 mm, L/D = 38.5) for the inner core, while propylene for the outer sheath A homopolymer (trade name: Sumitomo Noblene U501E1, manufactured by Sumitomo Chemical Co., Ltd., MI=120 g/10 min) was fed to a single-screw extruder (VS40, manufactured by IKEGAI Ltd.: 40 mmφ, L/D= 25). From these extruders, the blend for the core and the resin for the sheath were fed to a core/sheath die at a temperature of 250°C at a core/sheath ratio of 90/10 ( with six outlets). The extruded six-strand strands were cooled by a water bath, and then cut with a pelletizer to obtain double-layered pellets with a diameter of 2 to 3 mm and a length of 3 to 4 mm. The MI of the obtained double-layer pellets was 1500 g/10 min. The maleic anhydride graft-modified polypropylene forming the inner core had a graft ratio of 0.2% by weight and an MI of 3000 g/10 min.

Example 2

To 100 parts by weight of propylene homopolymer (trade name: Noblene HA100E, manufactured by SumitomoChemical Co., Ltd., MI=300g/10min), 12 parts by weight of 2-hydroxyethyl methacrylate, 3 parts by weight tert-butyl peroxybenzoate (active oxygen = 8.1%, decomposition temperature = 169° C. providing a half-life of 1 min), 1.2 parts by weight of styrene monomer, 0.2 parts by weight of Irganox 1010 manufactured by Ciba Specialty Chemicals, 0.2 parts by weight Irgafos 168 manufactured by Ciba Specialty Chemicals and 5 parts by weight of organic porous powder (trade name = MP-1000, manufactured by MEMBRANA) were mixed well at room temperature to obtain a blend.

The blend was fed into a twin-screw extruder (PCM46, manufactured by IKEGAI Ltd.; screw design: diameter = 46 mm, L/D = 38.5) for the inner core, while propylene for the outer sheath Homopolymer (trade name: Sumitomo Noblene U501E1, manufactured by Sumitomo Chemical Co., Ltd., MI = 120 g/10 min) was fed to a single-screw extruder (VS40, manufactured by IKEGAI Ltd.; screw design: diameter = 40 mm , L/D=25). From these extruders, the blend for the core and the resin for the sheath were fed to a core/sheath die at a temperature of 220°C at a core/sheath ratio of 97/3 ( with six outlets). The extruded six-strand strands were cooled by a water bath, and then cut with a pelletizer to obtain double-layered pellets with a diameter of 2 to 3 mm and a length of 3 to 4 mm. The MI of the obtained double-layered pellets was 1000 g/10 min. The graft ratio of (2-hydroxyethyl methacrylate)-graft-modified polypropylene forming the inner core was 3.5% by weight and MI was 1400 g/10 min.

Comparative example 1

To 100 parts by weight of propylene homopolymer (trade name: Noblene HA100E, manufactured by SumitomoChemical Co., Ltd., MI=300g/10min), 12 parts by weight of 2-hydroxyethyl methacrylate, 3 parts by weight tert-butyl peroxybenzoate (active oxygen = 8.1%, decomposition temperature = 169° C. providing a half-life of 1 min), 1.2 parts by weight of styrene monomer, 0.2 parts by weight of Irganox 1010 manufactured by Ciba Specialty Chemicals, 0.2 parts by weight Irgafos 168 manufactured by Ciba Specialty Chemicals and 5 parts by weight of organic porous powder (trade name = MP-1000, manufactured by MEMBRANA) were mixed well at room temperature to obtain a blend.

The blend was fed into a twin-screw extruder for inner core (PCM46, manufactured by IKEGAI Ltd.; screw design: diameter=46mm, L/D=38.5), and then from the extruder in A temperature of 220°C was fed to a core/sheath die (with six outlets). The extruded six-strand strand consisting only of the inner core had low melt tension, making it difficult to draw the strand, and no pellets were obtained.

Example 3

To 100 parts by weight of ethylene-propylene random copolymer (manufactured by Sumitomo Chemical Co., Ltd., MI=0.5g/10min, ethylene content=0.3% by weight), 15 parts by weight of maleic anhydride, 2.8 parts by weight Parts of di(hexadecyl) peroxydicarbonate (active oxygen = 2.8%, providing 1min half-life decomposition temperature = 99 ° C), 0.15 parts by weight of 1,3-bis (tert-butylperoxyisopropyl ) benzene (active oxygen = 9.3%, providing 1min half-life decomposition temperature = 183 ° C), 0.05 parts by weight of calcium stearate, 0.3 parts by weight of tetrakis [methylene-3-(3,5-di-tert-butyl Base-4-hydroxyphenyl) propionate] methane (antioxidant) and 3 parts by weight of styrene monomer, and fully mixed at room temperature to obtain a blend.

The blend was fed into a twin-screw extruder (PCM46, manufactured by IKEGAI Ltd.; screw design: diameter = 46 mm, L/D = 38.5) for the inner core, while propylene for the outer sheath Homopolymer (trade name: Sumitomo Noblene U501E1, manufactured by Sumitomo Chemical Co., Ltd., MI = 120 g/10 min) was fed to a single-screw extruder (VS40, manufactured by IKEGAI Ltd.; screw design: diameter = 40 mm , L/D=25). From these extruders, the blend for the core and the resin for the sheath were fed to a core/sheath die at a temperature of 250°C at a core/sheath ratio of 97/3 ( with six outlets). The extruded six-strand strands were cooled by a water bath, and then cut with a pelletizer to obtain double-layered pellets with a diameter of 2 to 3 mm and a length of 3 to 4 mm. The MI of the obtained bilayer pellets was 5 g/10 min. The graft ratio of the maleic anhydride graft-modified ethylene-propylene random copolymer forming the inner core was 2.4% by weight.

Comparative example 2

To 100 parts by weight of ethylene-propylene random copolymer (manufactured by Sumitomo Chemical Co., Ltd., MI=0.5g/10min, ethylene content=0.3% by weight), 15 parts by weight of maleic anhydride, 0.50 parts by weight Parts of di(hexadecyl) peroxydicarbonate (active oxygen = 2.8%, providing 1min half-life decomposition temperature = 99 ° C), 0.15 parts by weight of 1,3-bis (tert-butylperoxyisopropyl ) benzene (active oxygen = 9.3%, providing 1min half-life decomposition temperature = 183 ° C), 0.05 parts by weight of calcium stearate, 0.3 parts by weight of tetrakis [methylene-3-(3,5-di-tert-butyl Base-4-hydroxyphenyl) propionate] methane (antioxidant) and 3 parts by weight of styrene monomer, and fully mixed at room temperature to obtain a blend.

The blend was fed into a twin-screw extruder for inner core (PCM46, manufactured by IKEGAI Ltd.; screw design: diameter=46mm, L/D=38.5), and then from the extruder in Extruded at a temperature of 250°C. Pelletization was difficult due to strong odor, and no pellets were obtained.

Claims (15)

1. A multilayer pellet comprising an inner core of a first material comprising a first thermoplastic resin and an outer sheath of a second material comprising a second thermoplastic resin, said outer sheath surrounding said inner core , wherein the first thermoplastic resin has a melt index of 200 g/10 min or greater measured at a temperature of 230°C and a load of 21.2N, provided that the second thermoplastic resin is measured at a temperature of 230°C and a load of 21.2N has a melt index different from that of a first thermoplastic resin prepared by melting and kneading a thermoplastic resin as a raw material, a compound containing an unsaturated group, and an organic peroxide graft- Modified thermoplastic resins, Wherein said "thermoplastic resin" is a propylene polymer resin, The compound containing unsaturated group is selected from maleic anhydride, maleic acid, fumaric acid, itaconic anhydride, itaconic acid, glycidyl (meth)acrylate and 2-hydroxyethyl methacrylate ,and The unsaturated group-containing compound is used in an amount of 0.01 to 30 parts by weight based on 100 parts by weight of the thermoplastic resin as a raw material. 2. The multi-layer pellet according to claim 1, wherein the weight ratio of said outer sheath to said inner core is 50/50 to 1/99. 3. The multilayer pellet according to claim 1, wherein the unsaturated group-containing compound further has a polar group. 4. A method of preparing a multilayer pellet comprising an inner core of a first material comprising a first thermoplastic resin and an outer sheath of a second material comprising a second thermoplastic resin, said An outer sheath surrounds said inner core, wherein the first thermoplastic resin has a melt index of 200 g/10 min or greater measured at a temperature of 230°C and a load of 21.2 N, provided that the second thermoplastic resin is at a temperature of 230°C and a melt index measured under a load of 21.2 N that is different from the melt index of a first thermoplastic resin, wherein said "thermoplastic resin" is a propylene polymer resin, the method comprising: Provided is a multilayer extruder having a die having a first extruded section through which a first material is extruded as an inner core and a second extruded section through which a second material is extruded as an outer sheath. an extrusion, a second extrusion disposed to surround the first extrusion; a first feeder for feeding a first material to the first extrusion; and a first feeder for feeding a second material to the first extrusion Second feeder for two extrusion sections, feeding the first material from the first feeder to the first extrusion section, feeding the second material from the second feeder to the second extrusion section, extruding the first material through the first extrusion section and extruding the second material through the second extrusion section to cover the first material with the second material to form a multilayer extrudate, and The multilayer extrudate is cut to predetermined lengths to form multilayer pellets. 5. The method according to claim 4, wherein the first thermoplastic resin is prepared in the first step by melting and kneading a thermoplastic resin as a raw material, a compound containing both an unsaturated group and a polar group, and an organic peroxide. feeder formed. 6. The method of claim 4, wherein the die is a crosshead die. 7. A multilayer pellet comprising an inner core of a first material comprising a first thermoplastic resin and an outer sheath of a second material comprising a second thermoplastic resin, said outer sheath surrounding said inner core , wherein the first thermoplastic resin is a modified thermoplastic resin having a structure derived from a compound containing an unsaturated group, Wherein said thermoplastic resin is propylene polymer resin, The compound containing unsaturated group is selected from maleic anhydride, maleic acid, fumaric acid, itaconic anhydride, itaconic acid, glycidyl (meth)acrylate and 2-hydroxyethyl methacrylate ,and The unsaturated group-containing compound is used in an amount of 0.01 to 30 parts by weight based on 100 parts by weight of the thermoplastic resin as a raw material. 8. The multilayer pellet according to claim 7, wherein the compound containing an unsaturated group further contains a polar group. 9. The multilayer pellet according to claim 7, wherein the weight ratio of said outer sheath to said inner core is 50/50 to 1/99. 10. The multilayer pellet according to claim 7, wherein the first thermoplastic resin is prepared by melt-kneading a thermoplastic resin as a raw material, a compound containing both an unsaturated group and a polar group, and an organic peroxide modified thermoplastic resins. 11. The multi-layered pellet according to claim 7, wherein the first thermoplastic resin is obtained by using 100 parts by weight of a thermoplastic resin as a raw material, 0.01 parts by weight or more of a compound containing both an unsaturated group and a polar group A modified thermoplastic resin prepared by melting and kneading a compound and 0.001 to 20 parts by weight of an organic peroxide. 12. The multilayer pellet of claim 7, wherein the first thermoplastic resin has a melt index of less than 200 g/10 min measured at a temperature of 230°C and a load of 21.2N. 13. A method of preparing a multilayer pellet comprising an inner core of a first material comprising a first thermoplastic resin and an outer sheath of a second material comprising a second thermoplastic resin, said An outer sheath surrounds the inner core, wherein the first thermoplastic resin is a modified thermoplastic resin having a structure derived from a compound containing an unsaturated group, wherein the thermoplastic resin is a propylene polymer resin, and the first thermoplastic resin contains The compound of the saturated group is selected from maleic anhydride, maleic acid, fumaric acid, itaconic anhydride, itaconic acid, glycidyl (meth)acrylate and 2-hydroxyethyl methacrylate, and, based on 100 parts by weight of thermoplastic resin as a raw material, the amount of compound containing unsaturated groups is 0.01 to 30 parts by weight, The method includes: Provided is a multilayer extruder having a die having a first extruded section through which a first material is extruded as an inner core and a second extruded section through which a second material is extruded as an outer sheath. an extrusion, a second extrusion disposed to surround the first extrusion; a first feeder for feeding a first material to the first extrusion; and a first feeder for feeding a second material to the first extrusion Second feeder for two extrusion sections, feeding the first material from the first feeder to the first extrusion section, feeding the second material from the second feeder to the second extrusion section, extruding the first material through the first extrusion section and extruding the second material through the second extrusion section to cover the first material with the second material to form a multilayer extrudate, and The multilayer extrudate is cut to predetermined lengths to form multilayer pellets. 14. The method according to claim 13, wherein the first thermoplastic resin is prepared in the first step by melting and kneading a thermoplastic resin as a raw material, a compound containing both an unsaturated group and a polar group, and an organic peroxide. formed in the feeder. 15. The method of claim 13, wherein the die is a crosshead die.