JP6750673B2 - Bloom bleed inhibitor, composition containing the same, and elastomer molded article - Google Patents

Description

TECHNICAL FIELD The present invention relates to a bloom/bleed inhibitor for suppressing bleeding or bloom of a compounding agent from a molded article (hereinafter, referred to as “elastomer molded article”) obtained by using a raw material composition containing rubber, elastomer and the like. ..

Conventionally, a raw material composition used for forming an elastomer molded article contains various additives in addition to rubber, elastomer and the like, depending on required performance. For example, in the case of mainly rubber, a process oil, a processing aid, an antioxidant, a vulcanization accelerator, etc. are blended, and in the case of mainly elastomer, an antioxidant, a light stabilizer, a plasticizer. And so on.
In recent years, while various performances of elastomer molded products have been improved, there have been cases where an additive is exposed over time. Such a phenomenon of blooming and bleeding not only deteriorates the appearance, but also cannot maintain the initial physical properties, or the elastomer molded products may adhere to each other, or the elastomer molded product and the packaging material may adhere to each other. Brought. Therefore, in order to suppress these problems, attempts have been made to add new additives to the raw material composition.

In Patent Document 1, 0 to 150 parts by weight of a process oil and a vulcanized rubber having a hardness of 70 or more per 100 parts by weight of a rubber base material containing an ethylene/propylene rubber composed of ethylene, propylene and a non-conjugated diene are used. In a rubber composition containing a filler mainly composed of black or carbon black and using 0.01 to 10 parts by weight of a dithioate compound as a vulcanization accelerator, 0.1 to 15 parts by weight of non-reactive phenol formaldehyde is used. A sulfur-vulcanizable high-hardness rubber composition characterized by adding a resin or polyethylene glycol is disclosed.
Patent Document 2 discloses a rubber based on an ethylene/propylene/diene terpolymer containing a sulfur-based vulcanizing agent and optionally a vulcanization accelerator, with a specific structure per 100 parts by weight of the base rubber. Disclosed is a rubber composition having an improved bloom phenomenon, which is characterized by comprising 0.2 to 10.0 parts by weight of the zinc dithiophosphate compound.
Patent Document 3 discloses a rubber product in which bloom due to an anti-aging agent is suppressed, wherein porous glass fibers having an anti-aging agent attached to the surface and pores thereof are compounded in a rubber compound. Has been done.
Patent Document 4 discloses a bleeding/bloom preventing agent which is blended in a raw material composition mainly composed of natural rubber, diene-based synthetic rubber or ethylene/propylene rubber, and which comprises a quaternary ammonium salt compound having a specific structure. It is disclosed.
Patent Document 5 discloses an ethylene/saturated carboxylic acid vinyl ester copolymer saponified alkylene oxide adduct and a polyether compound as a bloom inhibitor mixed in a raw material composition mainly composed of natural rubber or synthetic rubber. Are disclosed.
Further, in Patent Document 6, 100 parts by weight of a resin containing a polyolefin resin, 0.1 to 20 parts by weight of a layered silicate, and 0.01 to 5 parts by weight of a hindered amine light stabilizer and/or an ultraviolet absorber. The layered silicate contains at least a part of the monolayers of the layered crystals overlapping with each other by shifting the centers of the monolayer surfaces, and apparently becomes a flat plate having a thickness of 5 to 50 nm and a length of 500 nm or more. A weather-resistant resin composition characterized by being dispersed is disclosed.

JP, 57-18749, A JP-A-2-41345 Japanese Patent Laid-Open No. 3-119044 JP-A-3-139541 JP, 2000-265049, A JP, 2003-105202, A

An object of the present invention is to provide, from an elastomer molded article, a bloom/bleed inhibitor having an excellent effect of suppressing bleeding or bloom of a compounding agent, a composition containing the same, and an elastomer molded article.

The inventor of the present invention used the raw material composition containing a powder of an amorphous inorganic material, and in the obtained elastomer molded article, the occurrence of the bloom bleed phenomenon associated with the compounding agent such as an additive was suppressed. The present invention has been completed and the present invention has been completed.
The present invention is shown below.
1. A material for suppressing bleeding or bloom of a compounding agent from an elastomer molded article, which comprises a powder made of an amorphous inorganic material.
2. The bloom bleed inhibitor according to item 1, wherein the inorganic material is a compound represented by the following general formula (1).
aM ¹ ₂ O·bM ² O·cM ³ ₂ O ₃ ·dM ⁴ O ₂ ·eP ₂ O ₅ ·fH ₂ O (1)
(In the formula, M ¹ is an alkali metal atom, M ² is a divalent metal atom, M ³ is a trivalent metal atom, M ⁴ is a tetravalent metal atom, and each of a, b, c, d and e Among them, at least one is a positive number, the rest are 0 or a positive number, and f is a positive number.)
3. Item 3. The bloom bleed inhibitor according to Item 2, wherein M ² O in the general formula (1) is ZnO.
4. Item 3. The bloom bleed inhibitor according to Item 2, wherein M ³ ₂ O ₃ in the general formula (1) is Al ₂ O ₃ .
5. Item 5. The bloom bleed inhibitor according to any one of Items 1 to 4, wherein the powder has a specific surface area of 30 g/m ² or more.
6. A composition comprising the bloom bleed inhibitor according to any one of the above items 1 to 5 and an elastomer or an uncrosslinked rubber,
A composition in which the content of the bloom/bleed inhibitor is 0.5 to 10% by mass based on the entire composition.
7. An elastomer molded article obtained from the composition according to item 6.
8. A method for suppressing bleeding or blooming of a compounding agent from an elastomer molded article, using the bloom bleeding inhibitor according to any one of items 1 to 5 above.

In the present invention, the elastomer molded article is a molded article obtained by using a raw material composition (composition of the present invention) mainly containing an elastomer or uncrosslinked rubber and optionally containing a resin. Depending on the type of compounding agent contained in the raw material composition, the elastomer molded article may be a crosslinked product or a non-crosslinked product.

The bloom bleed inhibitor of the present invention can provide an elastomer molded article in which the occurrence of the bloom bleed phenomenon is suppressed.
Since the composition of the present invention contains a bloom bleed inhibitor composed of an amorphous inorganic powder, it is suitable for forming an elastomer molded article in which the occurrence of the bloom bleed phenomenon is suppressed. Further, when producing an elastomer molded article using the composition, it is possible to efficiently produce an elastomer molded article having a predetermined shape without causing alteration, decomposition, etc. and without reacting with other components. it can.
Since the elastomer molded article of the present invention contains the bloom bleed inhibitor composed of an amorphous inorganic powder, the bloom bleed phenomenon is less likely to occur over time during use or storage, and has excellent appearance over a long period of time.

Is a diagram illustrating a method for determining the half-width H of the X-ray diffraction peaks of _{0.01Al 2 O 3 · ZnO · 0.05H} 2 O powder is an example of an amorphous inorganic powder.

Hereinafter, the present invention will be described in detail.
The bloom bleed inhibitor of the present invention contains a powder made of an amorphous inorganic material (hereinafter referred to as "amorphous inorganic powder"). The bloom bleed inhibitor of the present invention may be composed only of an amorphous inorganic powder, or may be composed of an amorphous inorganic powder and another powder as long as the occurrence of the bloom bleed phenomenon is suppressed. It may be one.
In the present invention, the term "amorphous" means that a peak detected in an X-ray diffraction image obtained by powder X-ray diffraction measurement is not observed, or even if it is observed, the half-value width of the peak is 0.5 degree or more. It is of low crystalline quality. Figure 1 is a type of amorphous inorganic material, an X-ray diffraction pattern of the powder consisting of _{0.01Al 2 O 3 · ZnO · 0.05H} 2 O, semi the characteristic diffraction peaks in 31.7degree It is the schematic which shows the method of calculating|requiring price range H, and shows that H is about 0.8 degrees.

The amorphous inorganic material is not particularly limited, and an oxide containing at least one metal atom selected from an alkali metal atom, a divalent metal atom, a trivalent metal atom, and a tetravalent metal atom, or an oxide thereof. The compound represented by the following general formula (1) is preferable.
aM ¹ ₂ O·bM ² O·cM ³ ₂ O ₃ ·dM ⁴ O ₂ ·eP ₂ O ₅ ·fH ₂ O (1)
(In the formula, M ¹ is an alkali metal atom, M ² is a divalent metal atom, M ³ is a trivalent metal atom, M ⁴ is a tetravalent metal atom, and each of a, b, c, d and e Among them, at least one is a positive number, the rest are 0 or a positive number, and f is a positive number.)

In the above general formula (1), M ¹ is an alkali metal atom, and examples thereof include Li, Na, K, Rb and Cs. Of these, Na is preferred. M ² is a divalent metal atom, and examples thereof include alkaline earth metal atoms such as Be, Mg, Ca and Ba, Cu, Zn, Fe, Co, Ni, Ru, Pd, Pt, Pb and Cd. Of these, Mg and Zn are preferable. M ³ is a trivalent metal atom, and examples thereof include Al and Fe. Of these, Al is preferable. Further, M ⁴ is a tetravalent metal atom, and examples thereof include Si, Ti, and Zr. Of these, Si is preferable.
In addition, M ¹ , M ² , M ³ or M ⁴ constituting the general formula (1) may be only one kind, or may be two or more kinds.

Specific examples of the compound represented by the general formula (1) are represented by the following formulas (1-1) to (1-16). In the following formula, a, b, c, d and e are 0 or a positive number, f is a positive number, b=b ₁ +b ₂ , c=c ₁ +c ₂ , d=d ₁ +d ₂ .
^{_{aM 1 2 O · dSiO 2 ·}} fH 2 O (1-1)
^{_{aM 1 2 O · bM 2 O}} · dSiO 2 · fH 2 O (1-2)
^{_{aM 1 2 O · cM 3 2}} O 3 · dSiO 2 · fH 2 O (1-3)
^{_{aM 1 2 O · d 1 M}} 4 O 2 · d 2 SiO 2 · fH 2 O (1-4)
^{_{aM 1 2 O · bM 2 O}} · eP 2 O 5 · fH 2 O (1-5)
^{_{aM 1 2 O · cM 3 2}} O 3 · eP 2 O 5 · fH 2 O (1-6)
^{_{aM 1 2 O · dM 4 O}} 2 · eP 2 O 5 · fH 2 O (1-7)
^{_{aM 1 2 O · bM 2 O}} · cAl 2 O 3 · fH 2 O (1-8)
^{_{aM 1 2 O · c 1 M}} 3 2 O 3 · c 2 Al 2 O 3 · fH 2 O (1-9)
^{_{aM 1 2 O · dM 4 O}} 2 · cAl 2 O 3 · fH 2 O (1-10)
^{_{aM 1 2 O · bZnO · fH}} 2 O (1-11)
cM ³ ₂ O ₃ .bZnO.fH ₂ O (1-12)
^{_{aM 1 2 O · b 1 M}} 2 O · b 2 ZnO · fH 2 O (1-13)
^{_{aM 1 2 O · cM 3 2}} O 3 · bZnO · fH 2 O (1-14)
^{_{aM 1 2 O · dZrO 2 ·}} fH 2 O (1-15)
^{_{aM 1 2 O · dTiO 2 ·}} fH 2 O (1-16)

In the present invention, the compounds represented by the general formulas (1-1), (1-2), (1-3), (1-11), (1-12) and (1-13) are It is particularly preferable because it has an excellent effect of suppressing the occurrence of the bloom/bleed phenomenon. Specific compounds are exemplified below.
0.1Na ₂ O・SiO ₂・0.1H ₂ O
Na ₂ O/0.01MgO/SiO ₂ /0.1H ₂ O
Na ₂ O/0.2Al ₂ O ₃ /SiO ₂ /0.1H ₂ O
0.13Na ₂ O・Al ₂ O ₃・8.2SiO ₂・0.7H ₂ O
0.1Na ₂ O/ZnO/0.1H ₂ O
ZnO・0.27H ₂ O
0.2Na ₂ O/0.1MgO/ZnO/0.1H ₂ O
0.007Al ₂ O ₃ ·ZnO ·0.02H ₂ O
0.007Al ₂ O ₃ ·ZnO ·0.15H ₂ O

The shape and particle size of the amorphous inorganic powder are not particularly limited. The median particle diameter measured by a laser diffraction type particle size distribution machine is preferably about 0.1 to 20 μm. Particularly preferably, the dispersibility and processability of the raw material composition used for producing the elastomer molded product and the effect of suppressing the occurrence of the bloom and bleed phenomenon in the obtained elastomer molded product are reliably obtained. It is 5 to 15 μm.

The specific surface area of the amorphous inorganic powder is preferably 30 g/m ² or more, more preferably 50 m ² /g or more, since the effect of suppressing the occurrence of the bloom/bleed phenomenon in the elastomer molded product can be sufficiently obtained. more preferably ^{80 m} 2 / g or more, particularly preferably 100~450m ² / g. The specific surface area of the amorphous inorganic powder can be measured by the BET method.

As described above, the bloom bleed inhibitor of the present invention may contain a powder (another powder) made of another inorganic material or an organic material. In this case, the bloom bleed inhibitor of the present invention The lower limit of the content ratio of the amorphous inorganic powder contained is preferably 50% by mass, more preferably 80% by mass.

The composition of the present invention (hereinafter referred to as "raw material composition") is characterized by containing the above-described bloom/bleed inhibitor of the present invention and an elastomer or an uncrosslinked rubber. The raw material composition of the present invention may further contain a resin, an additive, a solvent and the like. The resin may be either a thermoplastic resin or a curable resin. Hereinafter, the elastomer or uncrosslinked rubber will be collectively referred to as “polymer component” regardless of whether or not the resin is contained.

As the elastomer and the uncrosslinked rubber, a (co)polymer containing a structural unit derived from a diene compound or a hydrogenated product thereof (hereinafter referred to as "diene elastomer"); an olefin copolymer; an acrylic rubber; a urethane type Elastomers; polyester elastomers; polyamide elastomers and the like can be used.

The diene elastomer may further contain a structural unit derived from an aromatic vinyl compound, a structural unit derived from a vinyl cyanide compound, and the like.
Examples of the diene elastomer include polybutadiene rubber, polyisoprene rubber, styrene/butadiene copolymer rubber (SBR), chloroprene rubber (CR), acrylonitrile/butadiene rubber (NBR), isoprene/isobutylene copolymer rubber (IIR), styrene rubber. AB type diblock copolymer, styrene type ABA type triblock copolymer, styrene type ABAB type tetrablock copolymer, styrene type ABABA type pentablock copolymer, styrene type multiblock having AB repeating units of these or more Examples thereof include copolymers.

As the olefin copolymer, an ethylene unit and a structural unit derived from α-olefin, a copolymer containing a structural unit derived from a non-conjugated diene compound or a carboxylic anhydride modified product thereof (hereinafter, "It is referred to as "ethylene/α-olefin copolymer rubber"), a copolymer containing an ethylene unit and a structural unit derived from an unsaturated carboxylic acid, and the like.

Examples of the α-olefin relating to the ethylene/α-olefin copolymer rubber include propylene, 1-butene, 1-pentene, 1-hexene, and the like, and non-conjugated diene compounds include dicyclopentadiene and 5-ethylidene. 2-norbornene, 1,4-hexadiene, methyltetrahydroindene, methylnorbornene and the like can be mentioned.
Examples of the ethylene/α-olefin copolymer rubber include ethylene/propylene copolymer rubber, ethylene/butene copolymer rubber, ethylene/hexene copolymer rubber, and ethylene/octene copolymer rubber.

When the polymer component contains a resin, the resin is usually selected depending on the type of elastomer or uncrosslinked rubber. Examples of the resin include an olefin resin, an acrylic resin, and a resin containing a structural unit derived from an aromatic vinyl compound.

When the raw material composition of the present invention is produced, an elastomer molded body having a uniform composition can be efficiently obtained. Therefore, the amount of water in the Bloom/bleed inhibitor used is preferably 1 to 15% by mass, more preferably 1 to It is 10% by mass. The water content can be measured by the Karl Fischer method.

The content of the bloom bleed inhibitor in the raw material composition of the present invention is preferably 0.5 to 10% by mass, because the effect of suppressing the occurrence of the bloom bleed phenomenon in the elastomer molded product can be sufficiently obtained. It is preferably 1 to 8% by mass, more preferably 2 to 6% by mass. If the content exceeds 10 parts by mass, the elastomer molded product may have problems such as strength reduction and color tone change. In the present invention, the bloom bleed inhibitor may be used alone or in combination of two or more kinds.

The raw material composition of the present invention usually contains a compounding agent such as an additive and a solvent in order to improve processability and efficiently produce an elastomer molded article having a desired shape or characteristic.
As additives, antioxidants, ultraviolet absorbers, light stabilizers, antioxidants, plasticizers, flame retardants, antistatic agents, mildew-proofing agents, colorants, cross-linking agents (vulcanizing agents), vulcanization accelerators. , A vulcanization retarder, a pacifier, a processing aid such as stearic acid, a lubricant such as wax, a process oil, a tackifier, a filler, a methylene donor, and a methylene acceptor organic cobalt compound. Among these, components related to the bloom/bleed phenomenon are antioxidants, ultraviolet absorbers, light stabilizers, antiaging agents, plasticizers, flame retardants, antistatic agents, antifungal agents, vulcanization accelerators, processing aids. Agents, lubricants, process oils, etc.

Examples of the antioxidant include hindered amine compounds, hydroquinone compounds, hindered phenol compounds, sulfur-containing compounds, phosphorus-containing compounds and the like.
As the ultraviolet absorber, a benzophenone compound, a benzotriazole compound,
Examples thereof include triazine-based compounds.
Examples of the light stabilizer include hindered amine compounds.
Examples of the antioxidant include naphthylamine compounds, diphenylamine compounds, p-phenylenediamine compounds, quinoline compounds, hydroquinone derivative compounds, monophenol compounds, bisphenol compounds, trisphenol compounds, polyphenol compounds, thiol. Examples thereof include bisphenol type compounds, hindered phenol type compounds, phosphite type compounds, imidazole type compounds, dithiocarbamic acid nickel salt type compounds and phosphoric acid type compounds.

Examples of the plasticizer include phthalic acid ester, trimellitic acid ester, pyromellitic acid ester, aliphatic monobasic acid ester, aliphatic dibasic acid ester, phosphoric acid ester, polyhydric alcohol ester, epoxy plasticizer, high Examples include molecular type plasticizers and chlorinated paraffins.
Examples of the flame retardant include halogen-containing compounds, phosphorus-containing compounds and silicone compounds.
Examples of the vulcanization accelerator include zinc dimethyldithiocarbamate, zinc diethylthiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, Dithiocarbamate compounds such as tellurium diethyldithiocarbamate; Thiuram compounds such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethyluram disulfide, tetrabutylthiuram disulfide, dipentamethylenethiuram tetrasulfide; N-cyclohexyl-2-benzo Thiazolesulfenamide, N-oxydiethylene-2-benzothiazolesulfenamide, N,N-diisopropyl-2-benzothiazolesulfenamide, 2-mercaprobenzothiazole, 2-(2,4-dinitrophenyl)mercapto Thiazole compounds such as benzothiazole, 2-(2,6-diethyl-4-morpholinothio)benzothiazole, dibenzothiazole-dibenzothiazyl-disulfide; diphenylguanidine, triphenylguanidine, diorthotrilguanidine, orthotril-bi- Guanidine compounds such as guanide and diphenylguanidine phthalate; thiourea compounds such as thiocarbanilide, diethylthiourea, dibutylthiourea, trimethylthiourea, diorsotolylthiourea; aldehyde amines or aldehydes such as acetaldehyde-aniline condensates, hexamethylenetetramine, acetaldehyde ammonia. -Ammonia-based compounds; imidazoline-based compounds such as 2-mercaptoimidazoline; xanthate-based compounds such as zinc dibutylxanthate; zinc white and the like.
Examples of the process oil include naphthenic oil and paraffinic oil.

Examples of the filler include inorganic fillers such as silica, talc, calcium carbonate and carbon black; polymer fillers such as coumarone indene resin, high styrene resin and phenol resin.

When producing an elastomer molded article having a crosslinked structure, a crosslinking agent (vulcanizing agent) such as a sulfur compound or an organic peroxide is used.
Examples of the sulfur compounds include sulfur, sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, and selenium dimethyldithiocarbamate.
As the organic peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2, 5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, di-tert-butylperoxide, di-tert-butylperoxy-3,3,5-trimethylcyclohexane, tert-butylhydroperoxide and the like can be mentioned. To be

When an organic peroxide is used as the cross-linking agent, it is preferably used together with a cross-linking aid. As the cross-linking aid, sulfur; quinone dioxime compounds such as p-quinone dioxime; methacrylate compounds such as polyethylene glycol dimethacrylate; allyl compounds such as diallyl phthalate and triallyl cyanurate; maleimide compounds such as bismaleimide. Compounds: divinylbenzene and the like can be mentioned.
When a sulfur compound is used as the vulcanizing agent, it is preferably used in combination with the vulcanization accelerator.

The raw material composition of the present invention, for example, after the raw material components are kneaded by a closed kneading machine, an oven roll, an extruder, etc., the resulting kneaded product, if necessary, a crosslinking agent (vulcanizing agent) It can be produced by adding a vulcanization accelerator or the like. Here, as a method of using the raw material components, a method of using the whole amount at once, a Bloom bleed inhibitor and a compounding agent are mixed in advance, and then the obtained mixture is kneaded with an elastomer or an uncrosslinked rubber. It can be set as a method or the like.

The elastomer molded article of the present invention is an article obtained by using the above-mentioned raw material composition of the present invention. Specific manufacturing methods include injection molding, extrusion molding, inflation molding, vacuum molding, foam molding, and heat pressing. Therefore, the elastomer molded article of the present invention can be composed of a solid body or a foam, and in the solid portion, it is possible to suppress bloom bleed in a crosslinked polymer matrix or an uncrosslinked polymer matrix. It has a structure in which an agent and a component relating to the bloom bleed phenomenon included as a compounding agent in the raw material composition are dispersed and included.

The reason why the elastomer molded article containing the bloom bleed inhibitor of the present invention has the effect of suppressing the occurrence of the bloom bleed phenomenon is not known, but the present inventors have found that the bloom bleed inhibitor and the additive We believe that this is due to its high affinity with.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples. In addition, "%" is the mass %.

1. Evaluation Method (1) Powder X-Ray Diffraction of Bloom Bleed Inhibitor Powder X-ray diffraction was measured by Cu Kα ray using Rigaku X-ray diffractometer "RINT2400V" (model name), and X-ray diffraction was performed. Got the statue. The measurement conditions were a tube voltage of 40 kV and a current of 150 mA. The full width at half maximum of the obtained diffraction peak at the specific position (2θ) was determined by the method shown in FIG.
(2) Specific Surface Area of Bloom/Bleed Inhibitor According to JIS Z8830-2001, “Method for measuring specific surface area of powder (solid) by gas adsorption”, continuous flow type surface area meter “SA-6200” manufactured by Horiba Ltd. Name).
(3) Median particle size (d50) of the bloom/bleed inhibitor
The bloom bleed inhibitor was measured using a laser diffraction particle size distribution analyzer “MS2000” (model name) manufactured by Malvern Instruments Ltd., and the median particle diameter (d50) was measured on a volume basis.
(4) Test for confirming effect of suppressing bloom/bleed phenomenon 70 parts by mass of styrene-based tetrablock copolymer hydrogenated product, 30 parts by mass of styrene-based triblock copolymer hydrogenated product, and 20 parts by mass of Dry blend of polypropylene resin, 3 mass% or 6 mass% equivalent bloom/bleed inhibitor, and 0.5 mass part of carbon black with respect to the total of these polymer components using a Henschel mixer. did. Next, 100 parts by mass of naphthenic oil was added and mixed sufficiently to obtain a raw material composition. Then, the raw material pellet was produced by melt-kneading at about 200° C. using an extruder. Then, using an injection molding machine, a plate-shaped test piece (11 mm×11 mm×1 mm) was obtained at 170° C. Then, it was stored at 50° C. for 2 weeks. The surface of the plate-shaped test piece before and after storage was visually observed and evaluated according to the following criteria.
◯: No bleeding or iridescent coloring phenomenon was observed ×: Bleeding or iridescent coloring phenomenon was remarkable

2. Preparation of Composition Containing Bloom/Bleed Inhibitor, Preparation and Evaluation of Test Piece (Elastomer Molded Article) Examples 1 and 2
As a bloom bleed inhibitor, 31.7 deg. The half-value width of the diffraction peak at about 0.8 deg. 0.007Al ₂ O ₃ .ZnO.0.15H ₂ O powder (specific surface area: 104 m ² /g, median particle size: 1.7 μm) was used, and this was 3% by mass with respect to the total of the polymer components. Alternatively, a raw material composition containing 6% by mass was prepared. Then, a test for confirming the effect of suppressing the bloom/bleed phenomenon was conducted (see Table 1).

Example 3
As a bloom/bleed suppressor, ZnO.0.27H ₂ O powder (specific surface area: 188 m ² /g, median particle size: 9.8 μm) in which a clear diffraction peak was not detected in an X-ray diffraction image was used. A raw material composition containing 3 mass% of this was prepared. Then, a test for confirming the effect of suppressing the bloom/bleed phenomenon was conducted (see Table 1).

Example 4
As Bloom bleed inhibitor, 0.13Na to clear diffraction peak in X-ray diffraction pattern is not detected _{2 O · Al 2 O 3 ·} 8.2SiO 2 · 0.7H 2 O powder (specific surface area: 245m ² / g, Using a median particle diameter of 7.9 μm), a raw material composition containing 3% by mass of the polymer component was prepared. Then, a test for confirming the effect of suppressing the bloom/bleed phenomenon was conducted (see Table 1).

Comparative Example 1
As a bloom bleed inhibitor, 31.7 deg. The half-value width of the diffraction peak at 0.1 deg. A powder (specific surface area: 0.4 m ² /g, median particle size: 0.3 μm) made of zinc oxide (hereinafter, referred to as “zinc oxide (I)”) is used for the total amount of polymer components. A raw material composition containing 3% by mass was prepared. Then, a test for confirming the effect of suppressing the bloom/bleed phenomenon was conducted (see Table 1).

Comparative example 2
As a bloom bleed inhibitor, 31.7 deg. The half width of the diffraction peak at 0.3 deg. A powder (specific surface area: 20 m ² /g, median particle diameter: 0.2 μm) made of zinc oxide (hereinafter, referred to as “zinc oxide (II)”) was used, and this was 3 A raw material composition containing mass% was prepared. Then, a test for confirming the effect of suppressing the bloom/bleed phenomenon was conducted (see Table 1).

Comparative Example 3
As a bloom bleed inhibitor, an X-ray diffraction image of 9.4 deg. Half width of the diffraction peak at 0.2 deg. Of talc powder (specific surface area: 22 m ² /g, median particle size: 7.8 μm) was used to prepare a raw material composition containing 3% by mass of the total amount of polymer components. Then, a test for confirming the effect of suppressing the bloom/bleed phenomenon was conducted (see Table 1).

Comparative Example 4
A plate-shaped test piece was prepared using only an elastomer containing no bloom/bleed inhibitor, and a test for confirming the bloom/bleed phenomenon suppression effect was conducted (see Table 1).

As is clear from Table 1, the bloom bleed inhibitors used in Examples 1 to 4 provide elastomer molded products having a bloom bleed phenomenon suppression effect over a long period of time.

By using the bloom/bleed inhibitor of the present invention or the composition containing the same, problems such as poor appearance of various elastomer molded products can be suppressed, and thus deterioration of physical properties and the like can be suppressed. Therefore, the bloom bleed inhibitor of the present invention or the composition containing the same is used for a long period of time in various fields such as vehicle field, OA/home appliances field, electric/electronic field, medical field, tools, daily sundries and the like. It is suitable for forming members. Specific examples of elastomer molded products include gaskets, cap seals, tubes, noise reduction gears, grips for tools, toothbrushes, pens, razors, grips for cutters, shoe soles, handbrake grip covers, shift knobs, armrests, assists. Examples include grips and toys.

Claims (5)

From an elastomer molded article containing an elastomer containing a hydrogenated product of a copolymer containing a structural unit derived from a diene compound and a structural unit derived from an aromatic vinyl compound, and a compounding agent containing a naphthenic oil , A material for suppressing bleeding or bloom of a compounding agent, which contains a powder of an inorganic material, wherein the inorganic material is a compound represented by the following general formula (1), and by powder X-ray diffraction measurement: A bloom bleed inhibitor having a low crystallinity in which the peak detected in the obtained X-ray diffraction image is not observed, or even if it is observed, the half-width of the peak is 0.5 degree or more.
aNa ₂ O·bZnO·cAl ₂ O ₃ ·dSiO ₂ · fH ₂ O (1)
(In the formula, a, b, c, d are 0 or a positive number, and at least one of b and c is a positive number and f is a positive number.) The bloom bleed inhibitor according to claim 1, wherein the powder has a specific surface area of 30 g/m ² or more. An elastomer containing a bloom bleed inhibitor according to claim 1 or 2 , a hydrogenated product of a copolymer containing a structural unit derived from a diene compound and a structural unit derived from an aromatic vinyl compound, and a naphthene type. A composition comprising an oil-containing compounding agent, wherein the content of the bloom bleeding inhibitor is 0.5 to 10% by mass based on the entire composition. An elastomer molded article obtained from the composition according to claim 3 . An elastomer containing a hydrogenated product of a copolymer containing a structural unit derived from a diene compound and a structural unit derived from an aromatic vinyl compound , using the Bloom bleed inhibitor according to claim 1 or 2 . A method for suppressing bleeding or bloom of the above-mentioned compounding agent from an elastomer molded article containing the compounding agent containing a naphthenic oil .

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