JP2000302937A - Soft resin pellet - Google Patents

Abstract

(57) [Problem] To improve the handling property of a soft resin pellet while maintaining the characteristics of the soft resin. SOLUTION: The glass transition temperature is 20 ° C or lower and the gel content is 40% by weight or lower (meth) acrylic acid ester-based copolymer (A) 25 to 90 parts by weight, and the glass transition temperature is 50 ° C. 5 to 75 parts by weight of the above copolymer (b) and 5 to 95% by weight of the rubber polymer (R) and 5 to 95% by weight of a vinyl monomer are polymerized with a graft copolymer (C) 0 to 100 parts by weight of a soft resin pellet comprising 70 parts by weight (100 parts by weight in total of (a), (b) and (c)) and having a hardness of 30 to 100 on the surface of the molded body at 20 ° C. according to JIS K6301 method To the lubricant 0.0
01 to 2 parts by weight are deposited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft resin pellet having remarkably excellent handleability (easiness of handling) in molding. Specifically, a (meth) acrylate copolymer having a glass transition temperature of 20 ° C. or lower and a gel content of 40% by weight or less, a copolymer having a glass transition temperature of 50 ° C. or higher, and rubber weight The present invention relates to a soft resin pellet obtained by adhering a small amount of a lubricant (B) as an essential component to a pellet of a soft resin (A) made of a graft copolymer obtained by polymerizing a vinyl monomer with a coalesced polymer.

[0002]

2. Description of the Related Art Vinyl chloride resins are inexpensive and have an excellent balance of quality. Therefore, they are thermoplastic resins used in various fields such as hard fields and soft fields. Examples include pipes and joints, window frames, industrial transparent plates, films, etc., and in the field of soft materials, electric wire coatings, wrap films, sheets, and the like.

[0003] A vinyl chloride resin as a material is a general-purpose resin which is indispensable to be inexpensive. However, various characteristics are required also in terms of performance. Plasticizer absorption and suppression of fish eyes.

On the other hand, in the field of hard applications, good workability and thermal stability when processing into various molded articles, and good basic physical properties such as tensile strength and impact strength after molding are required. Various attempts have been made to improve these required characteristics, and many can be seen in the techniques disclosed so far. For example, JP-A-9-27896
JP-A-10-1584 discloses a method of adding a methyl methacrylate-butadiene-styrene copolymer or chlorinated polyethylene to a vinyl chloride resin in order to improve impact resistance and molding processability. A method of adding a calcium compound, a zinc compound, an epoxidized vegetable oil, a β-diketone compound and an ester compound to a vinyl chloride resin in order to improve thermal stability and processability;
Japanese Patent Application No. 17744 discloses a method of blending a chlorinated polyolefin and / or a vinyl ester-ethylene copolymer with a vinyl chloride resin in order to improve moldability.

However, all of these methods contain various reinforcing agents and additives, and generally require a large amount of various reinforcing agents and additives. Furthermore, when polymerizing polyvinyl chloride resin, various scales are used to prevent scale from adhering to the inner wall of the polymerization vessel, the inner wall of the monomer reflux unit, and the inner wall of the piping in the system, causing deterioration in quality and poor heat removal during polymerization. It is polymerized by applying a scale inhibitor.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and improve the handling properties of pellets while maintaining the characteristics of a soft resin.

[0007]

Means for Solving the Problems The present inventors have intensively studied a method for improving the handling properties of soft resin pellets. As a result, if a small amount of lubricant is adhered to the resin pellets, the softness and mechanical properties are reduced. It has been found that, while maintaining the above, blocking of the thermoplastic resin pellets can be remarkably suppressed, and the biting defect of the pellets at the screw portion of the molding machine does not occur.

That is, the present invention has a glass transition temperature of 2
(Meth) acrylate copolymer (a) having a temperature of 0 ° C. or less and a gel content of 40% by weight or less (a) 25 to 9
0 parts by weight, 5 to 75 parts by weight of a copolymer (b) having a glass transition temperature of 50 ° C. or more, and 5 to 9 of a rubber polymer (R)
A graft copolymer (c) obtained by polymerizing 5 to 95% by weight of a vinyl monomer to 5% by weight (0) to 70 parts by weight ((a);
(B) and (c) 100 parts by weight in total)
Pellets 10 of a soft resin (A) having a hardness of the molded body surface at 20 ° C. of 30 to 100 according to JIS K6301 method
The soft resin according to claim 1, wherein the soft resin pellet (claim 1) and the copolymer (b) are a styrene-based resin in which 0.001 to 2 parts by weight of the lubricant (B) is attached to 0 part by weight. The pellet (Claim 2) and the (meth) acrylate-based copolymer (A) are composed of the (meth) acrylate 40
To 98% by weight, 2 to 60% by weight of an aromatic vinyl compound, 0 to 40% by weight of a vinyl cyanide compound, and 0 to 40% by weight of a monomer copolymerizable therewith (total 100% by weight)
3. The soft resin pellet according to claim 1 or claim 2 which is a copolymer obtained by polymerizing (b) a copolymer comprising 10 to 95% by weight of an aromatic vinyl compound and 0 to 0% of a vinyl cyanide compound. 45% by weight, 0 to 50% by weight of a maleimide monomer, and 0 to 40% by weight of a monomer copolymerizable therewith
4. The soft resin pellet according to claim 1, 2 or 3, which is a copolymer obtained by polymerizing (total 100% by weight), and the graft copolymer (c), having a volume average particle size of 30 to At least one rubber polymer (R) selected from the group consisting of a 2000 nm diene rubber polymer, an olefin rubber polymer, an acrylic rubber polymer, and a silicone rubber polymer (R) has a fragrance of 5 to 95 parts by weight. 5 to 90% by weight of a vinyl group compound, 10 to 95% by weight of a (meth) acrylate and / or vinyl cyanide compound, and 0 to 30% by weight of a monomer copolymerizable therewith (total 1).
The soft resin pellet according to claim 1, which is a copolymer obtained by polymerizing 5 to 95 parts by weight of a monomer mixture consisting of (00% by weight).

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The most important point in the present invention is that
This is to make the lubricant (B) adhere to the pellets composed of the soft resin (A) component. Adhesion refers to a state in which a lubricant is sprayed on the pellets, agitated, and a state in which the lubricant is uniformly dispersed on the outer surface of the pellets.The lubricant is mixed with the pellets and kneaded with a melt kneader such as an extruder, This is different from a state in which the lubricant is uniformly dispersed inside the pellet. The method of adhering the lubricant (B) to the pellets is not particularly limited, but preferably the lubricant is sprayed at a pellet temperature of 50 ° C. or higher, and the pellets are uniformly spread on the outer surface of the pellet using a device such as a blender that is usually used for stirring. Preferably, it is attached.

[0010] Specific examples of the lubricant (B) which is adhered to the pellet comprising the component (A) to improve the handling properties of the pellet while maintaining softness and mechanical properties include organopolysiloxane and polyethylene wax. , Polypropylene wax, polyester wax,
Polyamide wax, stearic acid, magnesium stearate, calcium stearate, ethylene bisstearyl amide, monostearyl glyceride, trisstearyl glyceride, butyl stearate, palmityl palmitate, stearyl stearate, behenyl behenate, stearyl montanate, stearyl amide And silicone waxes such as palmitic acid, olefin waxes, condensation polymerization waxes, fatty acids, fatty acid metals, fatty acid esters, and fatty acid amides, and known lubricants usually used for styrene resins can be used. The lubricant (B) can be used alone or in combination of two or more. The lubricant (B) preferably has a melting point of 300 ° C. or less, more preferably 2 ° C., from the viewpoint of uniform adhesion to the pellet.
A lubricant at 50 ° C. or lower is preferred.

The amount of component (B) used in the present invention is 0.001-2 parts by weight, preferably 0.003-1.5 parts by weight, and more preferably 100 parts by weight of soft resin pellet (A). It is 0.005 to 1 part by weight. If the amount is less than 0.001 part by weight, the blocking of the pellet cannot be sufficiently improved. If the amount is more than 2 parts by weight, the mechanical properties such as tensile strength are significantly reduced, and furthermore, the penetration of the pellet in the screw portion of the molding machine is poor. Insufficient filling occurs.

Further, in addition to the lubricant (B), other additives may be used in combination to adhere to the pellets. Specific examples of additives include stabilizers, antioxidants, ultraviolet absorbers, antistatic agents, antibacterial and antifungal agents, flame retardants, coloring agents, deodorants, fragrances, neutron blocking agents, degradability imparting agents, and inorganic reinforcement. Agents and the like, which can be used to obtain higher performance as a molding resin. The amount of other additives is 0.001 to 3 parts by weight, more preferably 0.01 to 2 parts by weight, based on 100 parts by weight of the soft resin pellet (A) from the viewpoint of handling properties.

The important component of the soft resin (A) component in the present invention is a (meth) acrylate copolymer (a). The (meth) acrylate copolymer (a) has a glass transition temperature of 20 ° C or lower, preferably -80 ° C to 10 ° C, more preferably -70 ° C to 0 ° C.
It is. If the glass transition temperature exceeds 20 ° C., the softness is significantly reduced.

The (meth) acrylic acid ester-based copolymer (a) preferably contains 40 to 98% by weight, more preferably 45 to 95% by weight of (meth) acrylic acid ester from the viewpoint of softness and workability. More preferably, 50 to 90% by weight, preferably 0 to 40% by weight, more preferably 0 to 35% by weight, particularly preferably 0 to 33% by weight of the vinyl cyanide compound, and preferably 2 to 33% by weight of the aromatic vinyl compound.
60% by weight, preferably 3 to 40% by weight, more preferably 5 to 32% by weight, and preferably 0 to 40% by weight, more preferably 0 to 3% by weight of a monomer copolymerizable therewith.
It is a copolymer obtained by polymerizing 0% by weight, particularly preferably 0 to 20% by weight, more preferably 0 to 15% by weight (total 100% by weight).

The (meth) acrylate copolymer (a) has a gel content (methyl ethyl ketone, 2% solution, left at 23 ° C. for 24 hours) from the viewpoint of softness and fluidity.
Filtration through a 100 mesh wire mesh to dry the filtration residue,
(A value represented by (filtration residue weight / original weight) × 100) is 40% by weight or less, preferably 30% by weight or less, more preferably 20% by weight or less and 10% by weight or less. If it exceeds 40% by weight, the softness and the fluidity are remarkably reduced.

Further, the reduced viscosity of the methyl ethyl ketone soluble portion of the (meth) acrylic ester copolymer (a) (3)
0 ° C. in an N, N-dimethylformamide solution) is preferably 0.3 to 5 dl / g, particularly preferably 0.4 to 4 dl / g, and more preferably 0.1 to 4 dl / g, from the viewpoint of tensile strength.
45 to 3 dl / g.

Examples of the (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxylethyl (meth) acrylate, glycidyl (meth) acrylate and the like can be mentioned. Of these, butyl (meth) acrylate is preferred from an industrial point of view. These may be used alone or in combination of two or more.

Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile. Of these, acrylonitrile is preferred from an industrial viewpoint.
These may be used alone or in combination of two or more.

As the aromatic vinyl compound, styrene,
Examples thereof include α-methylstyrene, p-methylstyrene, vinylnaphthalene, chlorostyrene, and bromostyrene. Of these, styrene is preferred from an industrial viewpoint. These may be used alone or in combination of two or more.

Examples of the copolymerizable monomer include maleimide, N-methylmaleimide, N-ethylmaleimide, and N-ethylmaleimide.
Maleimide monomers such as -propylmaleimide, N-butylmaleimide, N-phenylmaleimide, N- (p-methylphenyl) maleimide, allyl methacrylate,
Polyfunctional vinyl monomers having two or more polymerizable vinyl functional groups in a molecule such as polyethylene glycol dimethacrylate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, and (meth) acrylic acid And its 2-hydroxylethyl (meth) acrylate. These may be used alone or in combination of two or more.

The copolymer (b) of the present invention has a glass transition temperature of 50 ° C. or higher, preferably 80 ° C. or higher, more preferably 95 ° C. or higher, and further preferably 110 ° C. or higher. If the glass transition temperature is less than 50 ° C., the shape retention and softness during heating are reduced.

The copolymer (b) is a copolymer having a glass transition temperature of 50 ° C. or higher, for example, polystyrene, styrene-acrylonitrile copolymer, α-methylstyrene-acrylonitrile copolymer, styrene-α −
Methylstyrene-acrylonitrile copolymer, styrene-maleimide copolymer, styrene-maleimide-acrylonitrile copolymer, styrene-α-methylstyrene-
Styrene resins such as a maleimide-acrylonitrile copolymer and a styrene-maleic anhydride copolymer are exemplified. From the viewpoint of impact resistance, at least one monomer selected from the group consisting of a vinyl cyanide compound, an aromatic vinyl compound, a (meth) acrylic acid ester, and a maleimide compound is polymerized, and methyl ethyl ketone soluble components are reduced. Viscosity (3
0 ° C., in N, N-dimethylformamide solution)
２2 dl / g, more preferably 0.4 to 1.5 dl / g, particularly preferably 0.45 to 1.2 dl / g. In particular, the copolymer (b) is preferably from 10 to 95% by weight, more preferably from 10 to 85% by weight of the aromatic vinyl compound from the viewpoint of mechanical properties and processability.
% By weight, 0 to 45% by weight of a vinyl cyanide compound, more preferably 10 to 40% by weight,
50% by weight, more preferably 5 to 45% by weight, and preferably 0 to 40% by weight of a monomer copolymerizable therewith, more preferably 0 to 30% by weight, particularly preferably 0 to 20% by weight, (Total 100% by weight).

As the vinyl cyanide compound of the copolymer (b), acrylonitrile, methacrylonitrile and the like are used. As the aromatic vinyl compound, styrene, α-methylstyrene, p-methylstyrene, p-isopropylstyrene, chlorostyrene and the like are used. Styrene, bromostyrene, vinylnaphthalene, and the like, and maleimide-based monomers include maleimide, N-methylmaleimide, N-ethylmaleimide,
-Propylmaleimide, N-butylmaleimide, N-phenylmaleimide, N- (p-methylphenyl) maleimide and the like. From an industrial viewpoint, acrylonitrile is particularly preferred as the vinyl cyanide compound, styrene and α-methylstyrene as the aromatic vinyl compound, and N-phenylmaleimide as the maleimide-based monomer. These are used alone or in combination of two or more. Examples of the copolymerizable monomer include (meth) acrylic acid and its methyl, ethyl, propyl, butyl,
And (meth) acrylate monomers such as hydroxylethyl, 2-ethylhexyl and glycidyl. These may be used alone or in combination of two or more.

Further, polymer alloys using these copolymers, such as alloys of styrene-acrylonitrile copolymer and vinyl chloride resin, alloys of styrene-acrylonitrile copolymer and polycarbonate, styrene-acrylonitrile copolymer, The effects of the present invention can also be exerted when an alloy of a styrene resin such as an alloy of nylon 6, an alloy of polyethylene terephthalate and polycarbonate, or an alloy of polystyrene and polyphenylene oxide is used as the copolymer (b).

The rubber polymer (R) in the graft copolymer (C) preferably has a volume average particle size of 30 to 2000 n.
m, particularly preferably 50 to 1500 nm, more preferably 80 to 1000 nm, at least one rubber selected from the group consisting of diene rubber polymers, olefin rubber polymers, acrylic rubber polymers and silicone rubber polymers. It is a polymer. The rubber copolymer (R) of the graft copolymer (C) has a volume average particle size of less than 30 nm, or 20
If it exceeds 00 nm, mechanical properties such as tensile strength tend to decrease. The rubber polymer (R) may be a mixture of two or more kinds having different volume average particle diameters.

Specific examples of the rubber polymer (R) include diene rubber polymers such as polybutadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, butadiene-acrylate rubber, hydrogenated styrene-butadiene rubber, and ethylene. -Olefin polymers such as propylene rubber, ethylene-propylene-diene rubber, acrylic rubber polymers such as polyacrylate rubber and ethylene-acrylate rubber, polydimethylsiloxane rubber, polydimethylsiloxane-acryl composite rubber, etc. Silicone rubber polymers can be used, and these can be used alone or in combination of two or more. In the rubber polymer (R), from the viewpoint of weather resistance, it is preferable that the polyacrylate rubber and the silicone rubber polymer have 25% by weight or more, more preferably 40% by weight or more in the rubber polymer. Further, the rubber polymer (R) is preferably produced by an enlargement method using an acid group-containing latex (S).

The rubber polymer (R) is a rubber latex 10
5 to 50% by weight of an unsaturated acid (c) of at least one of acrylic acid, methacrylic acid, itaconic acid and crotonic acid with respect to 0 parts by weight (solid content), and an alkyl group having 1 to 12 carbon atoms. Acid group-containing latex prepared by polymerizing 50 to 95% by weight of at least one (meth) alkyl acrylate (d) and 0 to 40% of a monomer copolymerizable with (c) and (d) The rubber polymer produced by the coagulation enlargement method using is preferred.

The graft copolymer (C) is used in an amount of 5 to 95 parts by weight, preferably 10 to 90 parts by weight, of the rubber polymer (R).
More preferably, 15 to 85 parts by weight of the vinyl monomer 5
It is obtained by polymerizing -95 parts by weight, preferably 10-90 parts by weight, more preferably 15-85 parts by weight. As the vinyl monomer, the aromatic vinyl compound is preferably 5 to 90% by weight, more preferably 10 to 85% by weight, particularly preferably 15 to 80% by weight, and (meth) acrylic acid ester and / or vinyl cyanide. 10-95% by weight of compound
Is preferably 15 to 90% by weight, more preferably 20 to 85% by weight, and preferably 0 to 30% by weight of a monomer copolymerizable therewith, more preferably 0 to 20% by weight, and particularly preferably Is 0 to 15% by weight
(Total 100% by weight). Outside these ranges, mechanical properties and workability tend to decrease.

Acrylonitrile, methacrylonitrile and the like are used as the vinyl cyanide compound of the graft copolymer (C), and styrene and α are used as the aromatic vinyl compound.
-Methylstyrene, p-methylstyrene, p-isopropylstyrene, chlorostyrene, bromostyrene, vinylnaphthalene and the like. From an industrial point of view, acrylonitrile is particularly preferred as the vinyl cyanide compound, and styrene is particularly preferred as the aromatic vinyl compound. Examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and glycidyl (meth) acrylate. Is raised. Of these, methyl methacrylate is preferred from an industrial point of view. These may be used alone or in combination of two or more. Examples of the copolymerizable monomer include maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-butylmaleimide,
N-phenylmaleimide, N- (p-methylphenyl)
Maleimide monomers such as maleimide; (meth) acrylic acid; and the like. These may be used alone or in combination of two or more.

The soft resin (A) of the present invention contains 25 to 90 parts by weight of the (meth) acrylate copolymer (a), preferably 30 to 85 parts by weight, more preferably 33 to 85 parts by weight from the viewpoint of softness. 83 parts by weight, 5 to 75 parts by weight, preferably 15 to 70 parts by weight, particularly preferably 1 to 70 parts by weight of the copolymer (b)
7 to 67 parts by weight, and the graft copolymer (C) 0 to 70
Parts by weight, preferably 10 to 70 parts by weight, more preferably 13 to 65 parts by weight, and still more preferably 15 to 63 parts by weight (a total of (a), (b) and (c) is 100 parts by weight). Outside the range, the softness or the shape retention during heating is reduced.

The most important of the soft resin (A) of the present invention is the hardness at 20 ° C. according to the JIS K6301 method.
The soft resin (A) which is the thermoplastic resin composition of the present invention comprises:
Hardness at 20 ° C according to JIS K6301 method is 30-100
From the viewpoint of softness, preferably from 40 to 98, and more preferably from 45 to 95.

If the composition of the present invention is obtained, the (meth) acrylate-based copolymer (a), the copolymer (b), and the graft copolymer (c) can be prepared by any polymerization method, initiator, and chain transfer. It may be manufactured using an agent or a surfactant. For example, known bulk polymerization, solution polymerization, suspension polymerization,
Any one produced by any polymerization method such as an emulsion polymerization method, an emulsion-suspension polymerization method, and an emulsion-bulk polymerization method may be used as long as the composition can be controlled within the range of the present invention. For the production of the graft copolymer (c), an emulsion polymerization method is preferable because the graft ratio can be easily controlled. Furthermore, from the viewpoint of microstructure control and industrial point of view, (meth) acrylate-based copolymer (a),
Emulsion polymerization is preferred for both the copolymer (b) and the graft copolymer (c). Further, when polymerizing the (meth) acrylate-based copolymer (a) and the copolymer (b) by the emulsion polymerization method, the polymerization is carried out in the same polymerization system from the viewpoint of productivity and heat deformability. Is preferred. Particularly, a method of polymerizing the copolymer (b) after polymerizing the (meth) acrylic ester-based copolymer (a), or a method of polymerizing a part of the copolymer (b), and then polymerizing the (meth) acrylic acid It is preferable to polymerize the ester-based copolymer (a) and polymerize the remainder of the copolymer (b).

If the soft resin (A) of the present invention is obtained, the (meth) acrylate-based copolymer (a), the copolymer (b) and the graft copolymer (c) can be used in any starting materials. It may be manufactured using an agent, a chain transfer agent, and an emulsifier. The initiator is a thermal decomposition initiator such as potassium persulfate;
Known initiators such as e-reducing agents and redox initiators such as organic peroxides can be used. Known chain transfer agents such as t-dodecyl mercaptan, n-dodecyl mercaptan, α-methylstyrene dimer and terpinolene can be used. Examples of the emulsifier include fatty acid metal salt-based emulsifiers such as sodium oleate, sodium palmitate, and sodium rosinate, sodium dodecylbenzenesulfonate, and having 12 to 12 carbon atoms.
Known emulsifiers such as sulfonic acid metal salt-based emulsifiers such as 20 alkyl sodium sulfonate and sodium dioctyl sulfosuccinate can be used.

Further, polymers other than the (meth) acrylate-based copolymers (a), (b) and graft copolymers (c) of the present invention, such as NBR (nitrile butadiene rubber) General-purpose rubber polymers, styrene-based thermoplastic elastomers such as styrene-butadiene block copolymers, olefin-based thermoplastic elastomers, PVC-based thermoplastic elastomers, urethane-based thermoplastic elastomers, ester-based thermoplastic elastomers, and amide-based thermoplastics Known thermoplastic elastomers such as elastomers and polyphenylene oxide, polyphenylene sulfide,
Polysulfone, polyarylate, polyetherketone,
Other thermoplastic resins such as polyimides and thermosetting resins such as phenol resins can be added and used according to the purpose.

The soft resin (A) used in the present invention may be a well-known antioxidant, heat stabilizer, ultraviolet absorber,
Pigments, antistatic agents, and lubricants can be appropriately kneaded and used as necessary. Kneading is a Banbury mixer, roll mill,
Using a known machine such as a single screw extruder and a twin screw extruder,
This refers to the work of melting and kneading resin powder. In particular, phenolic, sulfur-based, phosphorus-based, hindered amine-based stabilizers, antioxidants, benzophenone-based, benzotriazole-based ultraviolet absorbers and organopolysiloxanes used in styrene-based resins, aliphatic hydrocarbons, higher fatty acids and Esters of higher alcohols, amides or bisamides of higher fatty acids and modified products thereof, oligoamides, internal lubricants such as metal salts of higher fatty acids, and external lubricants can be used as molding resins for higher performance. .

These stabilizers can be used alone or in combination of two or more.

The resin mixture of the (meth) acrylate-based copolymer (a), the copolymer (b), and the graft copolymer (c) varies depending on the production method. , Solutions, powders, pellets, etc., or a combination thereof. When polymer powder is recovered from the latex of the (meth) acrylate-based copolymer (a), the latex of the copolymer (b) and the latex of the graft copolymer (c) after polymerization, a usual method is used. For example, in latex, calcium chloride, magnesium chloride, alkaline earth metal salts such as magnesium sulfate, sodium chloride, alkali metal salts such as sodium sulfate,
The latex can be coagulated by adding an inorganic acid and an organic acid such as hydrochloric acid, sulfuric acid, phosphoric acid, and acetic acid, and then dehydrated and dried. Also, a spray drying method can be used.

Some of the stabilizers used may be added in the form of a dispersion to a latex or slurry of these resins.

The soft resin (A) used in the present invention comprises:
For the powder or pellet comprising the (meth) acrylic ester copolymer (a), the copolymer (b), the graft copolymer (c) alone or a mixture of two or more thereof, If necessary, a lubricant, a pigment and the like can be blended and kneaded.

The soft resin pellet of the present invention can be obtained by injection molding,
It can be molded by a known molding method such as extrusion molding (film molding, sheet molding, molding of irregular shaped products, etc.), blow molding, vacuum molding, calendar molding, compression molding, transfer molding, thermoforming, flow molding, lamination molding.

The soft resin pellet of the present invention can be used for applications requiring a soft resin in a wide range of fields such as automobiles, home appliances, and building materials.

[0042]

EXAMPLES Hereinafter, the present invention will be described with reference to specific examples, but these examples do not limit the present invention. In the examples, "parts" indicates parts by weight, and "%" indicates% by weight. The abbreviations of the compounds in the examples show the following compounds.

BA: butyl acrylate 2EHA: 2-ethylhexyl acrylate AN: acrylonitrile St: styrene tDM: t-dodecyl mercaptan CHP: cumene hydroperoxide PMI: N-phenylmaleimide αMSt: α-methylstyrene BMA: butyl methacrylate MAA: methacrylic acid GMA : Glycidyl methacrylate DSN: Dioctyl sodium sulfosuccinate

(1) Production of (meth) acrylate copolymer (a) and copolymer (b) (meth) acrylate copolymer (a-1) Stirrer, reflux condenser, In a reactor equipped with a nitrogen inlet, monomer inlet and thermometer, 250 parts of pure water, DSN
1.0 part, sodium formaldehyde sulfoxylate 0.5 part, EDTA 0.01 part, ferrous sulfate 0.1 part
0025 parts were charged.

The reactor was stirred at 65 ° C. under a nitrogen stream.
Temperature. After reaching 65 ° C., the first-stage monomer mixture shown in Table 1 (ratio BA 75%, AN 20%, St
5%), tDM and CHP were continuously added dropwise over 6 hours. In addition, DSN was added 0.5 hours after the second drop of the monomer.
And 4 hours later, 0.5 part was added. After dropping, 65 ° C
For 1 hour to complete the polymerization of the first stage (copolymer (a-1)).

Production of copolymer (b-1) Subsequently, the monomer mixture of the second stage (copolymer (b-1)) shown in Table 2 (ratio PMI 27%, AN 18%, St)
(7%, αMSt 48%), 25 parts, tDM and CHP were continuously added dropwise over 2 hours. After completion of the dropwise addition, stirring was continued at 65 ° C. for 1 hour to complete the second-stage polymerization.

(Meth) acrylic ester copolymers (A-2) to (A-6) and copolymers (B-2) to (B-2)
5) Production of the (meth) acrylate copolymer (a)
1) and the copolymer (b-1) was produced in the same manner as in the formulation shown in Tables 1 and 2 by the same method. However, the ratios of the copolymer (a) and the copolymer (b) were as shown in Tables 4 and 5. Like the copolymer (a-1) and the copolymer (b-1), the dropping time of the monomer was a total of 8 hours in the first and second stages (12.5 parts dropping rate per hour). After the completion of the dropping of the first-stage monomer and the completion of the dropping of the second-stage monomer, a stirring time of 1 hour was provided for each.

Tables 1 and 2 show the results.

[0049]

[Table 1]

[0050]

[Table 2]

(2) Preparation of graft copolymer (c) Rubber polymers (r-1), (r-2), (r-3) and An acid group-containing latex (S) was produced.

Rubber polymer (r-1) In a 100 L polymerization machine, 230 parts of pure water and potassium persulfate were added.
0.2 part and tDM 0.2 part were charged.

After removing the air in the polymerization machine with a vacuum pump,
0.6 parts of sodium oleate, sodium rosinate
2 parts and 100 parts of butadiene were charged.

The temperature of the system was raised to 60 ° C. to initiate polymerization. The polymerization was completed in 25 hours. 96% polymerization conversion,
The rubber average particle size of the unexpanded rubber polymer (r-1) latex was 85 nm.

Rubber polymer (r-2) 200 parts of pure water and 0.55 part of sodium palmitate were charged into a reactor equipped with a stirrer, a reflux condenser, a nitrogen inlet, a monomer inlet, and a thermometer. It is. The reactor was heated to 60 ° C. under a nitrogen stream while stirring. After the temperature rise,
Sodium formaldehyde sulfoxylate 0.3
, 0.0025 part of ferrous sulfate and 0.01 part of disodium ethylenediaminetetraacetate. Further, B
A 98.5 parts, TAC 1.5 parts, CHP 0.3 part monomer mixture was added dropwise over 6 hours.
Stirring was continued at 1 ° C for 1 hour to complete the polymerization. At 1.5 hours after dropping the monomer mixture, 0.3 parts of sodium palmitate was added. At 4 hours after dropping, 0.35% of sodium palmitate was added.
Parts were added. The polymerization conversion was 98%, and the rubber average particle size of the unexpanded rubber polymer (r-2) latex was 92 nm.

Rubber polymer (r-3) 200 parts of pure water, 1 part of sodium dodecylbenzenesulfonate, 100 parts of octamethylcyclotetrasiloxane
Part, 2 parts of tetraethoxysilane and 0.5 part of γ-methacryloyloxypropyldimethoxymethylsilane were emulsified and dispersed with a homogenizer to obtain an organosiloxane latex.

After degassing the inside of the polymerization machine and purging with nitrogen, the latex of the aforementioned organosiloxane was charged into the polymerization machine.
The temperature was raised to 80 ° C. and 0.2 g of dodecylbenzenesulfonic acid was added.
After stirring for 5 hours, the mixture was allowed to stand at 23 ° C. for 24 hours, and then neutralized with sodium hydroxide to complete the polymerization.
The polymerization conversion was 90%, and the obtained rubber latex (r-
The average rubber particle diameter of 3) was 130 nm.

Acid Group-Containing Latex (S) An acid group-containing latex (S) required for enlarging the rubber polymer (r) to the rubber polymer (R) was produced as follows.

A reactor equipped with a stirrer, a reflux condenser, a nitrogen inlet, a monomer inlet, and a thermometer was charged with pure water 200.
Part, sodium dioctyl sulfosuccinate 0.6 part,
Sodium formaldehyde sulfoxylate 0.5
Parts, 0.01 parts of sodium ethylenediaminetetraacetate,
0.0025 part of ferrous sulfate was charged.

The reactor was stirred at 70 ° C. under a nitrogen stream.
Temperature. After reaching 70 ° C, 25 parts of BMA, B
A 5 parts, a tDM 0.1 part, and a CHP 0.15 part monomer mixture were added dropwise over 2 hours, and then BMA 50
Part, BA 4 part, MAA 16 part, tDM 0.5 part, C
0.15 parts of HP was added dropwise over 4 hours.
Stirring was continued at 70 ° C. for 1 hour to terminate the polymerization to obtain an acid group-containing latex (S).

Rubber Polymer (R-1) Using the rubber polymers (r-1) and (r-2) produced above and the acid group-containing latex (S), a rubber polymer (R-1)
Was manufactured.

50 parts of a latex of rubber polymer (r-1) (solid content), 50 parts of a latex of (r-2) (solid content)
2.4 parts (solid content) of acid group-containing latex (S)
After addition at <RTIgt; C, </ RTI> stirring was continued for one hour to cause hypertrophy. The rubber average particle diameter of the obtained rubber polymer (R-1) latex is:
520 nm.

Rubber Polymers (R-2) and (R-3) The rubber polymers (r-2) and (r-3) shown in Table 3 were prepared in the same manner as the rubber polymer (R-1). ) And acid group-containing latex (S) to produce rubber polymers (R-2) and (R-3). The average rubber particle diameter of the obtained rubber polymer (R-2) latex was 380 nm, and the average rubber particle diameter of the rubber polymer (R-3) latex was 270 nm. Table 3 shows the results.

[0064]

[Table 3]

(2) Production of Graft Copolymer (C)-Graft copolymer (C-1) Pure water was added to a reactor equipped with a stirrer, reflux condenser, nitrogen inlet, monomer inlet, and thermometer. Water 280 parts, rubber polymer (R-1) (solid content) 65 parts, sodium formaldehyde sulfoxylate 0.3 parts, EDTA 0.01
Parts, and 0.0025 part of ferrous sulfate.

The reactor was stirred at 60 ° C. under a nitrogen stream.
Temperature. After reaching 60 ° C., 10 parts of AN, St 2
A mixture of 5 parts and 0.2 parts of CHP was continuously added dropwise over 5 hours. After completion of the dropwise addition, stirring was continued at 60 ° C. for 2 hours to terminate the polymerization, thereby obtaining a graft polymer (C-1). Table 4 shows the results.

Graft copolymers (C-2) and (C-2)
3) In the same manner as the graft copolymer (c-1), the rubber copolymer and the monomer mixture shown in Table 4 were used to produce the graft copolymers (c-2) and (c-3). did. Table 4 shows the results.

[0068]

[Table 4]

(3) Production of soft resin pellets to which lubricant (B) is adhered (meth) acrylate copolymer (a) produced in (1), copolymer (b), if necessary The latex of the graft copolymer (c) produced in (2) was mixed at a predetermined ratio shown in Table 5, and after adding a phenolic antioxidant, calcium chloride was added to coagulate. The solidified slurry was heat-treated, dehydrated and dried to obtain a mixed soft resin powder (a), (b) and (c). Phenolic antioxidant 0.5
Parts were blended and uniformly blended with a 20 L blender manufactured by Tabata Co., Ltd. Further, the mixture was melt-kneaded at 240 ° C. using a 40 m / m extruder manufactured by Tabata Co., Ltd. to produce resin composition pellets.

The prepared resin pellets were placed in a thermostat at 70 ° C.
After drying for 1 hour, heated resin pellets 10
0 parts were blended with the type and amount of the lubricant (B) shown in Tables 5 and 6 to obtain a soft resin pellet having the lubricant (B) adhered to the pellet surface.

As a comparative example, 0.5 parts of a phenolic antioxidant and Table 5 were added to the mixed soft resin powder (a), (b) and (c) obtained according to the above-mentioned Example.
After mixing the kind and amount of the lubricant (B) shown in 6 and uniformly blending with a 20 L blender manufactured by Tabata Co., Ltd., the mixture was melt-kneaded at 240 ° C. with a 40 m / m extruder manufactured by Tabata Co., Ltd. Soft resin pellets obtained by kneading a lubricant into the pellets were obtained.

[Calculation of Tg (Glass Transition Temperature)] The glass transition temperature of the acrylate copolymer (a) and the copolymer (b) can be calculated from the Tg of the homopolymer (literature value / Polymer handbook) using the Fox equation. Was calculated by

[Measurement of Gel Content] Calcium chloride was added to the (meth) acrylate-based copolymer (a) and the graft copolymer (c) latex for coagulation. The coagulated slurry was heat-treated, dehydrated and dried to obtain a 2% methyl ethyl ketone solution, left at 23 ° C. for 24 hours, filtered through a 100-mesh wire gauze, dried, and measured. It is represented by (weight of filtration residue / original weight) × 100.

[Measurement of Reduced Viscosity] Latex of (meth) acrylate copolymer (a) and (meth)
Acrylate copolymers (a) and copolymers (b)
Was coagulated by adding calcium chloride to the latex. The reduced viscosity was measured at 30 ° C. as a 0.3 g / dl N, N-dimethylformamide solution of a resin powder obtained by subjecting the coagulated slurry to heat treatment and dehydration drying. The reduced viscosity of the copolymer (b) is calculated from the reduced viscosity of the (meth) acrylate-based copolymer (a) and the (meth) acrylate-based copolymer (a) and the copolymer (b). It was calculated from the reduced viscosity of the resulting mixture by the arithmetic averaging method.

[Particle Size of Rubber Polymer] The rubber polymer latex was manufactured by Nikkiso Co., Ltd.
It was measured using a PA particle size analyzer.

[Conversion rate during polymerization] The conversion rate during polymerization was calculated from the solid content concentration.

[Characteristics of Soft Resin Pellets to which Lubricant (B) is Attached] Table 7 shows properties of the soft resin pellets to which the lubricant (B) obtained in the above (3) is attached. The measurement of each item was performed by the following method.

The hardness was measured at 20 ° C. based on JIS K6301 standard.

The compression set was measured under the conditions of 70 ° C. and 22 hours compression in accordance with JIS K6301 standard.

The tensile strength (unit: kg / cm ² ) and tensile elongation (unit:%) were evaluated at 23 ° C. using a No. 1 dumbbell according to ASTM D638 standard.

The shape retention during heating was measured by placing the dumbbell in a dryer at 80 ° C. for 8 hours and observing the change in shape. ○ (no change) and × (obvious shape change) were evaluated.

The test pieces used for the above-mentioned hardness, tensile strength, tensile elongation and shape retention during heating are FANUC Co., Ltd.
Using an AS100B injection molding machine, molding was carried out at the same cylinder temperature as in the extrusion pelletization, and was used for evaluation. The test piece of compression set was injection-molded, press-molded and cut to adjust to a prescribed shape.

The blocking property of the pellet was evaluated by the following method.

The produced pellets are made of hard vinyl chloride pipe (inner diameter 25 mm, height 300 mm, hereinafter abbreviated as PVC pipe).
Then, a PVC pipe was set upright with the cut surface facing down, left at 70 ° C. for 1 hour in a thermostat, and the blocking property immediately after being taken out of the thermostat was rated on a scale of 5 out of 5.

The rating of the blocking property is as follows.

5: The pellets fall out of the PVC pipe smoothly only by lifting the PVC pipe. 4: A part of the pellet remains in the PVC pipe just by lifting the PVC pipe, and then the pellet falls off by slightly tapping the PVC pipe from the side several times. 3: More than half of the pellet remains in the PVC pipe just by lifting the PVC pipe, and then the pellet falls off by gently tapping the PVC pipe several tens of times from the side. 2: Most of the pellet remains in the PVC pipe only by lifting the PVC pipe, and then the pellet falls off by hitting the PVC pipe vigorously several times from the side. 1: Almost all of the pellets remain in the PVC pipe just by lifting the PVC pipe, and then the pellet falls off by hitting the PVC pipe vigorously from the side several tens of times. 0: The pellets are completely fused to each other and cannot be removed from the PVC pipe.

The biteability of the pellets in the molding machine was determined by the ease of filling during injection molding.

○ (easy filling) and x (difficult to fill) were evaluated.

From the results shown in Table 7, the soft resin pellets to which the lubricant (B) of the present invention represented by Examples 1 to 15 adhered maintain softness, tensile strength, tensile elongation, and shape retention during heating. The handling of the pellets has been improved.

[0090]

[Table 5]

[0091]

[Table 6]

[0092]

[Table 7]

[0093]

According to the present invention, by adhering a small amount of lubricant to resin pellets, it is possible to significantly suppress blocking of thermoplastic resin pellets while maintaining softness and mechanical properties. Poor penetration of the pellets at the portions does not occur.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) C08L 51/06 C08L 51/06 51/08 51/08 F term (reference) 4F070 AA06 AA18 AA32 AB08 AE09 DA05 DA11 DA34 DA38 DA41 4J002 BC01W BC03X BC04W BC04X BC06W BC06X BC08W BC09W BC11W BG04W BG05W BG06W BG07W BH01X BN06Y BN12Y BN14Y BN15Y BN16Y BN17Y BN22Y CP034 EA016 EF0016 EG016 EF056 EG016 EF056 EG016

Claims (5)

[Claims] (1) 25-90 parts by weight of a (meth) acrylate copolymer (a) having a glass transition temperature of 20 ° C. or less and a gel content of 40% by weight or less, and a glass transition temperature of 50 ° C. 5 to 75 parts by weight of the above copolymer (b),
And a graft copolymer (c) obtained by polymerizing 5 to 95% by weight of a vinyl monomer with 5 to 95% by weight of a rubber polymer (R).
A soft resin (A) comprising 0 to 70 parts by weight (100 parts by weight in total of (a), (b) and (c)) and having a surface hardness of 30 to 100 at 20 ° C. according to JIS K6301 method. Lubricant (B) with respect to 100 parts by weight of the pellets
Soft resin pellets having 0.001 to 2 parts by weight attached thereto. 2. The soft resin pellet according to claim 1, wherein the copolymer (b) is a styrene resin. 3. The (meth) acrylate-based copolymer (a) comprises (meth) acrylate 40 to 98% by weight, an aromatic vinyl compound 2 to 60% by weight, and a vinyl cyanide compound 0 to 40% by weight. The soft resin pellet according to claim 1 or 2, which is a copolymer obtained by polymerizing 0 to 40% by weight (total 100% by weight) of a monomer copolymerizable therewith. 4. The copolymer (b) contains 10 to 95% by weight of an aromatic vinyl compound, 0 to 45% by weight of a vinyl cyanide compound, 0 to 50% by weight of a maleimide monomer, and is copolymerizable therewith. The soft resin pellet according to claim 1, 2 or 3, which is a copolymer obtained by polymerizing 0 to 40% by weight (total 100% by weight) of various monomers. 5. The graft copolymer (c) is selected from the group consisting of a diene rubber polymer, an olefin rubber polymer, an acrylic rubber polymer, and a silicon rubber polymer having a volume average particle diameter of 30 to 2000 nm. 5 to 90 parts by weight of at least one selected rubber polymer (R), 5 to 90% by weight of an aromatic vinyl compound, 10 to 95% by weight of a (meth) acrylate and / or a vinyl cyanide compound, and 5. A copolymer obtained by polymerizing 5 to 95 parts by weight of a monomer mixture consisting of 0 to 30% by weight (total 100% by weight) of a monomer copolymerizable with the polymer.
The soft resin pellet as described.