WO1998018860A1 - Latex of conjugated diene polymer rubber, rubber latex composition, and rubber foam - Google Patents

Abstract

A latex of a conjugated diene polymer rubber to which a mercapto compound of general formula (1) is bonded through the thiol group: (HS-R1-M-)n-R2 (wherein R1 is a C¿1?-C10 hydrocarbon group; M is -CO2- or -SO3-; n is an integer of 1 to 6; and when n is 1, R?2¿ is hydrogen, alkali metal, -NR¿4? (wherein R is H, alkyl or hydroxyalkyl), alkyl or alkoxyalkyl, while when n is 2 to 6, R?2¿ is a C¿2?-C18 organic group or a C2-C5 heterocyclic group). The latex is useful as the raw material for the production of foam.

Description

 Description ^ Latex of conjugated polymer rubber, rubber latex composition and rubber foam

 The present invention relates to a latex of a conjugated polymer rubber, a rubber latex composition containing the latex, and a rubber foam produced from the rubber latex composition.

 The latex of a conjugated polymer rubber of the present invention is a latex of a conjugated polymer rubber in which mercaptocarboxylic acid, mercaptosulfonic acid or a derivative thereof is bonded via a thiol group thereof. The latex is useful as a raw material for producing a foam having a balance between elasticity and strength. Background art

 Foams using rubber latex have been used in various fields. For example, foams made from natural rubber, acrylonitrile Z-butadiene copolymer rubber (NBR) and styrene / butadiene copolymer rubber (SBR) latex are used as materials for cosmetic puffs and sponge rolls. Have been.

 Among various foams, cosmetic puffs, in particular, are products that require a strict balance between strength and elasticity, but in recent years this balance has become increasingly strict, and conventional rubber latex meets this demand. Things have become difficult.

Polyurethane foam is a strong foam but has a poorer feel than foams derived from NBR latex and SBR latex. A combination of NBR and polyurethane has been proposed.However, when NBR latex and polyurethane emulsion are used together, there is no common vulcanizing agent and polyisocyanate, a crosslinking agent for polyurethane, is used. There is a problem that the compound does not function as a crosslinking agent in the presence of a large amount of water. The use of an acid-modified rubber latex copolymerized with a monomer having a propyloxyl group provides a foam with improved strength, but the texture is too hard and cannot be used for puff production. Disclosure of the invention

 In view of the above circumstances, an object of the present invention is to provide a rubber latex useful as a raw material for producing a foam having a high balance between strength and elasticity.

 Still another object of the present invention is to provide a rubber latex composition for producing a foam containing the useful rubber latex.

 Still another object of the present invention is to provide a rubber foam having a high balance between strength and elasticity.

 Thus, according to the present invention, there is provided a latex of a conjugated diene polymer rubber, wherein the latex is represented by the following formula (1):

(HS-R1-M-) _n -R2 (1)

 [In equation (1),

 o o

 II II

 M represents -C-〇- or -S-0-,

 II

 o

 Ri is an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may have a substituent (the aliphatic hydrocarbon group has a carboxyl group as a substituent when M is -CO-0-); Or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent.

n is, M is - CO- 0- 1 to 6 integer when, M is - S0 ₃ - 1 to represent each time,

R2 is when n == l, a hydrogen atom, an alkali metal, -NR ₄ (R is independently, you'll table a hydrogen atom or an alkyl or hydroxyalkyl group having a carbon number of 1-8.), The number of carbon atoms Represents an alkyl group having 1 to 15 or an alkoxyalkyl group having 2 to 8 carbon atoms, When n = 2 to 6, it represents a hydrocarbon group having 2 to 18 carbon atoms or a heterocyclic group having 2 to 5 carbon atoms. However, when n = 2, R ² may be an alkaline earth metal. ]

Wherein the at least one thiol compound represented by the formula is bonded to the polymer rubber molecule through the thiol group.

 Further, according to the present invention, there is provided a rubber latex composition for producing a foam, comprising a latex, a vulcanization system and, if necessary, a gelling agent of the conjugated gen-based polymer rubber.

 Further, according to the present invention, there is provided a rubber foam obtained by foaming and vulcanizing the above rubber latex composition. BEST MODE FOR CARRYING OUT THE INVENTION

 The conjugated gen-based polymer rubber latex used in the present invention is characterized in that at least one thiol compound represented by the above formula (1) is converted via its thiol group (more specifically, derived from the thiol group). Conjugated diene-based polymer is bonded to a carbon atom of a rubber molecule.

 The conjugated gen-based polymer rubber is a polymer rubber containing a conjugated gen monomer unit as an essential component, but is generally 40 to 90% by weight based on the weight of the polymer rubber. At least one unit selected from the group consisting of an ethylenically unsaturated nitrile monomer unit and an aromatic vinyl compound monomer unit; 10 to 60% by weight; and optionally, an unsaturated carboxylic acid unit of 0 to 10% by weight. And, if desired, a copolymer comprising 0 to 15% by weight of other ethylenically unsaturated monomer units.

 Specific examples of the conjugated gen include 1,3-butadiene, 2,3-dimethylbutadiene, isoprene, chloroprene, and 1,3-pentene. Conjugated gens can be used alone or in combination of two or more, and the amount used for copolymerization is usually in the range of 40 to 90% by weight based on the total amount of monomers.

Specific examples of ethylenically unsaturated nitriles copolymerized with conjugated gens include: Examples include rilonitrile, methacrylonitrile, and black acrylonitrile. These ethylenically unsaturated nitriles are used alone or in combination of two or more, and the amount is usually selected in the range of 10 to 60% by weight based on the total amount of the monomers. Further, specific examples of the aromatic vinyl compound include styrene, α-methylstyrene, vinylpyridine, vinyltoluene and the like. These aromatic vinyl compounds are used alone or in combination of two or more, and their amounts are usually selected in the range of 15 to 35% by weight based on the total amount of monomers. The type and amount of the ethylenically unsaturated nitrile and the aromatic vinyl compound are appropriately selected according to the required performance of the rubber foam.

 Specific examples of the unsaturated carboxylic acid optionally copolymerized with a conjugated diene include (meth) acrylic acid, maleic acid, itaconic acid and fumaric acid.

Other ethylenically unsaturated monomers optionally copolymerized with a conjugated diene include monoethylenically unsaturated monomers and polyfunctional ethylenically unsaturated monomers. Specific examples of the monoethylenically unsaturated monomer include those having 1 to 1 carbon atoms such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Alkyl acrylate and alkyl methacrylate having an alkyl group of 8; having an alkoxyalkyl group having 2 to 18 carbon atoms, such as methoxymethyl (meth) acrylate, ethoxyxyl (meth) acrylate, butoxyshethyl (meth) acrylate; Alkoxyalkyl acrylate and alkoxyalkyl methacrylate; hydroxyalkyl acrylate having a hydroxyalkyl group having 1 to 5 carbon atoms such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate And hi Aminoalkyl acrylates and aminoalkyl methacrylates having an aminoalkyl group having 3 to 12 carbon atoms, such as dimethylaminomethyl (meth) acrylate and dimethylaminoethyl (meth) acrylate; Aminohydroxyalkyl acrylates and aminohydroxyalkyl methacrylates having an aminohydroxyalkyl group having 3 to 12 carbon atoms, such as 3-getylamino-2-hydroxypropyl (meth) acrylate; Lysidyl (meth) acrylate; (meth) acrylamides such as (meth) acrylamide and N-methylol (methyl) acrylamide; and vinyl pyridine, vinylidene chloride, and biel acetate. Specific examples of polyfunctional ethylenically unsaturated monomers include non-conjugated diene such as divinylbenzene; vinyl norbornene and dicyclopentene; polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and the like. Di (meth) acrylate; trimethylolpropane tri (meth) acrylate, poly (meth) acrylate such as pentaerythritol tri (meth) acrylate, and the like. The above unsaturated carboxylic acids and ethylenically unsaturated monomers can be used alone or in combination of two or more, and their amounts are appropriately selected within a range that does not impair the effects of the present invention. Usually, the amount of unsaturated carboxylic acid is 10% by weight or less based on the total amount of monomers, and the amount of other ethylenically unsaturated monomers is 15% by weight or less based on the total amount of monomers. It is.

 The conjugated polymer rubber is prepared by copolymerizing the above monomer components by, for example, known emulsion polymerization.

 A reaction in which a compound having a thiol group is added to a carbon atom of a double bond in a conjugated gen-based polymer via a thioether bond (-S-) derived from the thiol group is represented by the following reaction formula. This reaction is known. The latex of the conjugated gen-based polymer rubber to which the thiol compound represented by the formula (1) used in the present invention is bonded is obtained by this reaction.

 -CH = CH- + R-S H → -CH2-CH-

S R

The thiol compound represented by the above formula (1) includes a mercaptocarboxylic acid represented by the formula HS-R1COOR ² and a derivative thereof;

(HS-RiC OO) a mercaptocarboxylic acid derivative having two or more thiol groups represented by nR ² [2≤n≤6]; and a mercaptosulfonic acid represented by the formula HS-RiSOsR ² and its derivatives Is included.

In each of the above formulas, Ri has 1 to 10 carbon atoms which may have a substituent, Or a linear or branched aliphatic hydrocarbon group having 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent. These aliphatic hydrocarbon groups and aromatic hydrocarbon groups may have a functional group such as a —C 00 H group or a —SH group. When two or more Ris are included, they may be the same or different.

In the above formula (1), in the case of n = l, R2 is hydrogen; sodium, Al force Li metal such as potassium © beam; expression such Anmoniumu group, hydroxy E chill § amino group - represented by NR ₄ An alkyl group having 1 to 15 carbon atoms such as a methyl group, an ethyl group or an octyl group; an alkoxyalkyl group having 2 to 8 carbon atoms such as a methoxymethyl group, an ethoxyxyl group and a 3-methoxybutyl group .

When 2≤n≤6, R2 represents an organic group having 2 to 18 carbon atoms or a heterocyclic group having 2 to 5 carbon atoms, having 2 to 6 bonds corresponding to n. The tool body Examples of such organic group, ethylene group, tetramethylene group, and _{- CH2CH2CH (CH 2 -) CH} 2 CH 2 -> -CH 2 C (CH 2 -) (CH 2 -) CH 2 - , etc. And a hydrocarbon group having a structure in which a hydroxyl group is removed from the polyhydric alcohol. Specific examples of the heterocyclic group having 2 to 5 carbon atoms include a tris (2-hydroxyethyl) isocyanurate residue. However, when n = 2, R ² may be an alkaline earth metal such as calcium.

Specific examples of the mercaptocarboxylic acid represented by the formula HS-R1COOR ² and derivatives thereof include thioglycolic acid, 3-mercaptopropionic acid, thiomalic acid, thiolactic acid (2-mercaptopropionic acid), methyl thioglycolate, and thioglycol. Octyl acid, 3-methoxybutyl thioglycolate, methyl 3-mercaptopropionate, octyl 3-mercaptopropionate, 3-methoxybutyl 3-mercaptopropionate, tridecyl 3-mercaptopropionate, ammonium thioglycolate, Monoethanolamine thioglycolate and sodium thioglycolate.

Specific examples of the mercaptocarboxylic acid derivative having two or more mercapto groups represented by the formula (HS- RiCOO) nR ² [2≤n≤6] include 1,4-butanediol. —Rubisthiodalicholate, ethylene glycol bisthioglycolate, trimethylolpropane tristhioglycolate, pentaerythritol tetrakisthioglycolate, 1,4-butanediol bis-3-mercaptopropionate, ethylene glycol bis- 3-mercaptopropionate, trimethylolpropane tris-3-mercaptopropionate, penyu erythritol tetrakis-3-mercaptopropionate, and trihydroxyethylisosyanurate tris-3-mercaptopropionate And the like.

Formula HS - as completely as examples of R i S Os mercapto sulfonic acid and its derivatives represented by R ^2, mercapto ethanesulfonic acid, mercapto sulfonic acid, sodium mercapto ethanesulfonic acid, and the like mercapto-propane sulfonic acid .

 At least one thiol compound represented by the above formula (1) is bonded to a carbon atom in the molecule via the thiol group (hereinafter referred to as “thiol-modified polymer rubber”). The addition of a thiol compound represented by the formula (1) to a conjugated diene polymer rubber in the form of a latex in the presence or absence of a catalyst at a temperature of room temperature to 120 ° C. Can be easily obtained by As the catalyst, persulfates, azo compounds such as azobisisobutyronitrile, and organic peroxides such as benzoyl peroxide are used. The thiol-modified polymer rubber latex of the present invention can be obtained directly as a reaction product of this addition reaction. When a conjugated gen-based polymer rubber is produced by emulsion polymerization, mercaptocarboxylic acid, mercaptosulfonic acid, or the like may be present in the polymerization system to cause an addition reaction simultaneously with the polymerization. In either case, a surfactant can be added to maintain the stability of the latex.

 Alternatively, a solution of a conjugated gen-based polymer rubber is prepared, a thiol compound represented by the formula (1) is added, an addition reaction is performed, and a solution of the obtained reaction product is converted to latex by phase inversion. Thereby, the latex of the thiol-modified polymer rubber of the present invention can be obtained.

At least one of the thiol-modified polymer rubbers of the present invention represented by the above formula (1) In order to remarkably improve the balance between the strength and elasticity of the obtained foam, the addition rate of the thiol compound of the kind is determined by the following method. The number of moles added to 0 is preferably 0.1 to 15 moles. When the addition ratio is less than 0.1 mol, a rubber foam having a high balance between strength and elasticity cannot be obtained. If the addition ratio exceeds 15 mol, the hand becomes hard, which is not preferable. A more preferred addition rate is 1 to 10 mol.

 The rubber latex composition for producing a foam of the present invention is obtained by mixing a latex of the thiol-modified polymer rubber with a vulcanizing system and, if necessary, a gelling agent. As the vulcanization system, any vulcanization system used in the production of ordinary foams using rubber latex as a raw material can be used, and is not particularly limited. As a specific example of the vulcanization system, a combination of sulfur as a vulcanizing agent, particularly colloidal sulfur, zinc white as a vulcanizing aid, and various vulcanization accelerators is most preferable. Examples of the vulcanization accelerator include thiazole accelerators such as 2-mercaptobenzothiazole and a zinc salt thereof, dibenzothiazyldisulfide, and dithiamine-based lubamate accelerator such as getyldithine zinc rubamate. And the like. The amount of the vulcanization system used is not particularly limited, but usually 0.1 to 10 parts by weight of sulfur, and 100 parts by weight of zinc rubber with respect to 100 parts by weight of the polymer rubber (solid content) in the latex. 0.5 to 10 parts by weight, the vulcanization accelerator varies depending on the type, but is about 0.1 to 5 parts by weight. These amounts are appropriately determined to satisfy the required performance of the foam.

Air is usually used to foam the rubber latex. If desired, a gelling agent is used to fix the foaming state. As the gelling agent, a silicon fluoride compound such as sodium hexafluorosilicate or hexafluorosilicate silica, and a thermosensitive gelling agent such as polyorganosiloxane are used. The amount of the gelling agent used is not particularly limited, but is usually about 0.5 to 10 parts by weight based on 100 parts by weight of the polymer rubber (solid content) in the latex. It is also possible to use a so-called freeze-coagulation method (Tararay method) without using a gelling agent. Various assistants can be added to the rubber latex, if desired. Antioxidants, coloring agents, foam stabilizers, and various compounding agents are stable in rubber latex as auxiliaries. Dispersing agents (eg, NASF [sodium salt of naphthalenesulfonic acid formalin condensate]), thickeners (eg, polyacrylic acid and its sodium salt, sodium alginate, polyvinyl alcohol, etc.), Surfactants as foaming agents (eg, fatty acid alkali soaps such as potassium oleate, higher alcohol sulfates such as sodium dodecyl sulfate) and the like.

 In order to prepare the rubber latex composition for producing a foam of the present invention, the above-mentioned compounding agent is compounded as a dispersion depending on the kind with the latex of the thiol-modified polymer rubber of the present invention, and is uniformly mixed.

 In order to produce a rubber foam from the rubber latex composition of the present invention, a conventionally known foaming method may be used. The method is not particularly limited.

 For example, the solid content concentration of the rubber latex composition for producing a foam is adjusted to about 45 to 65% by weight, and it varies depending on the use of the foam. For example, in the case of puff, the expansion ratio is 2 to 10%. Stir using a whisk while introducing air so that the volume becomes about twice. The composition having reached a predetermined expansion ratio is poured into a foaming mold, and vulcanization is performed in a heating chamber according to a predetermined temperature and time. The rubber foam thus obtained is sliced and cut into a predetermined thickness and shape, and the side is polished with a rotary grindstone to produce a puff.

 Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. Parts and percentages in the following are by weight unless otherwise specified.

 Example 1, Comparative Example 1

 [Production of thiol-modified NBR latex]

Acrylonitrile and butadiene were copolymerized by a usual emulsion polymerization method to obtain an acrylonitrile-butadiene copolymer rubber (NBR) latex (solid content: 55%) having an acrylonitrile content of 38%. 40 g of this NBR latex (solid content), 2 g of a polyoxyethylene noelphenol as a surfactant, 2.4 g of a thiol compound described in Table 1, and 0.4 g of benzoyl peroxide (BP〇). Put 5 g into a 100 m1 reaction vessel (ampoule), replace the inside with nitrogen, stopper tightly, and react for 18 hours while rotating the ampoule in a 50 ° C constant temperature water bath. Chio A modified NBR latex (Lxl to Lx5) was obtained. Table 1 shows the amount of the thiol compound used (the number of moles used per 100 double bonds in the polymer) and the addition ratio (the number of moles of the thiol compound added per 100 double bonds in the polymer). Show. As shown in Table 1, for example, in the case of NBR latex LX 1 modified with thioglycolic acid, 5.7 mol of thioglycolic acid was added to 100 double bonds in the butadiene monomer unit of NBR. When used, it shows that 3.7 moles were bonded to the double bond.

 In Comparative Example 1, the NBR latex was not modified with thiol (latex Lx 6).

 [Preparation and evaluation of vulcanized film]

 Using the thiol-modified NBR latex obtained as described above, a rubber latex composition was prepared according to the following formulation. From the obtained rubber latex composition, a vulcanized film was produced as follows, and the characteristics were measured. Table 1 shows the measurement results. Formulation Ml.

 Rubber latex (solid content) 100 Sulfur 2 Zinc white powder 3 Jetilditi Talented zinc rubamate 1 Mercaptobenzothiazol zinc salt 1 Composition of each rubber latex so that the dry thickness is about 0.5 mm on a glass plate The material was cast, air-dried, and peeled off from the glass plate to obtain a non-flowable film.

 Vulcanization was performed in an oven at 110 ° C. for 30 minutes.

 Evaluation method of film properties

 (1) Oil resistance

A 5 Omm long marked line is drawn on a strip-shaped test piece cut from the film, and this test piece is immersed in toluene and allowed to stand at room temperature for 5 hours. Then the test piece Take out, measure the length of the marked line, and display the percentage of extension to the original marked line length in%.

 (2) Tensile properties

Using a strip specimen cut from the film, the strain-stress curve was automatically recorded at a tensile speed of 50 Omm / min, and the stress at a given elongation, elongation at break (%) and breaking strength (kgZcm ² ) were determined. I read. For example, the stress at a predetermined elongation is expressed as 100% modulus (kg / cm2) in the case of a stress at 100% elongation.

 Example 2, Comparative example 2

Using the rubber latexes (Lx1 to Lx5 and Lx6) prepared in Example 1 and Comparative Example 1 respectively, rubber latex compositions for producing foams were prepared according to the following formulation. Formulation i

 Rubber latex (solid content) 100 Sulfur colloid 2 Zinc white 3 Zinc getyldithiocarbamate 1 Zinc mercaptobenzothiazole 1 Air mixed with rubber latex composition for foam production and foaming using Oaks mixer The mixture was stirred so that the magnification became 5 times, and 3 parts of sodium silicofluoride was added thereto. The obtained bubble-containing composition was poured into a stainless steel mold having a depth of 7 mm, and allowed to stand for 1 hour to allow gelation to proceed. Further, vulcanization was performed by heating in an oven at 110 ° C for 40 minutes. The properties of each of the obtained rubber foams were evaluated by the following methods.

 (1) Appearance

 The uniformity of foam in the foam was visually observed, and the following five-stage evaluation was performed.

 Grade 5: Very fine and uniform.

 4: Fine and uniform.

 3: Uniform.

 2: There is an uneven part.

 1: Uneven part is conspicuous.

 (2) Density (gZcmS)

 A 38 mm diameter disk is punched from the foam, its weight is measured and divided by volume.

(3) Compressive strength (gZcm2)

 Three specimens prepared in the same manner as for density measurement are stacked, and the stress is measured when the thickness is compressed by 25% at a compression speed of 2 OmmZmin. Divide this stress value by the cross-sectional area.

 (4) Breaking strength (kgZcm2) and elongation (%)

A test piece obtained by punching the foam with a No. 2 dumbbell (distance between marked lines: 2 Omm) was pulled at a pulling speed of 50 OmmZm in, and the strength at break (kgZcm2) and elongation (% ) Was measured.

 (5) Oil resistance

 Draw a 5 Omm long marking line on a strip-shaped foam test piece with a pole pen, immerse the test piece in toluene, and let it stand at room temperature for 1 hour. Then, remove the test piece, measure the length of the marked line, and indicate the percentage of extension to the original marked line length in%.

 Table 2

 Example 3, Comparative Example 3

 Using the NBR latex prepared in Example 1, as a thiol compound, thiodalicholic acid and ethylene darikol bisthiodali cholate were used in 6 parts and 1.8 parts (double bond, respectively) with respect to 100 parts of solid content of the latex. The number of moles used per 100 was 7.9 and 1.0, respectively.) The reaction was carried out in the same manner as in Example 1 except that thiol-modified NBR latex (Lx7) was used.

The NBR latex composition (Example 3) in which 2 parts of sulfur and 3 parts of zinc white were blended with 100 parts of the solid rubber content of the latex (Lx 7) and the solid of the unmodified NBR latex (Lx 6) of Comparative Example 1 2 parts sulfur and zinc for 100 parts rubber A rubber latex composition (Comparative Example 3) containing 3 parts of white flower was prepared, and a vulcanized film was prepared in the same manner as in Example 1 (vulcanization conditions: 100 minutes at 100 ° C.). Was evaluated. Table 3 shows the evaluation results together with the addition rate of the thiol compound. Table 3

 Example 4

 Using the thiol-modified NBR latex (Lx7) prepared in Example 3, a foam was produced in the same manner as in Example 2. This foam was equivalent to the foam of the present invention produced in Example 2. Industrial applicability

 The rubber foam produced from the thiol-modified rubber latex of the present invention has excellent elasticity and soft feel, and has high strength.

 Therefore, the rubber foam produced from the thiol-modified rubber latex of the present invention is useful for applications requiring a high balance between elasticity and strength. Particularly, it is suitable as a puff for cosmetics, a sponge mouth, and the like.

Claims

The scope of the claims 1. A latex of a conjugated polymer rubber having the following formula (1): (H S-Ri-M-) _n -R2 (1)  [In equation (1),  o o  II II  M represents -C_〇- or -S-O-,  II  o  Is an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may have a substituent (the aliphatic hydrocarbon group has a carboxyl group as a substituent when M is -CO-0-) Or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent. n is, M is - C_〇- 0 integer from 1 to 6 when, M is -S0 ₃ - 1 when represent respectively, R2 is when n = l, a hydrogen atom, an alkali metal, - NR ₄ (. R is independently representing a hydrogen atom or an alkyl or hydroxyalkyl group having 1 to 8 carbon atoms) from 1 to 1 to 5 carbon atoms Represents an alkyl group or an alkoxyalkyl group having 2 to 8 carbon atoms, When n == 2 to 6, it represents a hydrocarbon group having 2 to 18 carbon atoms or a heterocyclic ring having 2 to 5 carbon atoms. However, when n = 2, R ² may be an alkaline earth metal. ] Wherein the at least one thiol compound represented by the formula is bonded to the polymer rubber molecule via the thiol group.  2. In equation (1),  〇  II  M represents -C-0-, Is an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may have a substituent The aliphatic hydrocarbon group may have a carboxyl group as a substituent), or represents an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent,  n represents an integer of 1 to 6, R2 is when n = l, a hydrogen atom, an alkali metal, -NR ₄ (R is independently. Represents a hydrogen atom or an alkyl or hydroxyalkyl group having a carbon number of 1-8), 1-1 5 carbon atoms Represents an alkyl group or an alkoxyalkyl group having 2 to 8 carbon atoms, When n = 2 to 6, it represents a hydrocarbon group having 2 to 18 carbon atoms or a heterocyclic ring having 2 to 5 carbon atoms (however, when n = 2, R ² may be an alkaline earth metal The latex of the conjugated diene polymer rubber according to claim 1.  3. In equation (1),  Is an alkylene group having 1 to 5 carbon atoms (the alkylene group may have a carboxyl group as a substituent);  n is 1 and ^2. The latex of a co-polymer rubber according to claim 1, wherein R ² is a hydrogen atom or an ammonium group.  4. In equation (1),  Ri is an alkylene group having 1 to 3 carbon atoms (the alkylene group may have a carboxyl group as a substituent),  n is 1 and ^2. The latex of a co-polymer rubber according to claim 1, wherein R ² is a hydrogen atom or an ammonium group.  5. In equation (1),  〇  II  M is-S_〇-,  II O Ri is an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent, n is 1 and R ² is a hydrogen atom, an alkali metal, (R independently represents a hydrogen atom or an alkyl or hydroxyalkyl group having 1 to 8 carbon atoms.), An alkyl group having 1 to 15 carbon atoms or a total carbon number of 2 The latex of the conjugated diene polymer rubber according to claim 1, wherein the latex is an alkoxyalkyl group of from 8 to 8.  6. The addition rate of at least one thiol compound represented by the formula (1) to the conjugated polymer rubber is 0 per 100 double bonds of the conjugated monomer units in the polymer rubber. The latex of the conjugated polymer rubber according to any one of claims 1 to 5, wherein the latex is from 1 to 15 mol.  7. A conjugated gen-based polymer rubber to which at least one thiol compound represented by the formula (1) is bound, based on the weight of the polymer rubber, 40 to 90% by weight of a conjugated gen monomer unit, At least one unit selected from a saturated nitrile monomer unit and an aromatic vinyl compound monomer unit 10 to 60% by weight, an unsaturated carboxylic acid monomer unit 0 to 10% by weight, 7. The latex of a conjugated polymer rubber according to any one of claims 1 to 6, which is a copolymer comprising 0 to 15% by weight of a monoethylenically unsaturated monomer unit and other monoethylenically unsaturated monomer units.  8. The conjugated gen-based polymer rubber to which at least one thiol compound represented by the formula (1) is bonded is converted into an ethylenically unsaturated nitrile monomer unit in an amount of 10 to 60% by weight based on the weight of the polymer rubber. 8. A latex of a conjugated gen-based polymer rubber according to claim 7, which is a copolymer containing 15 to 35% by weight or an aromatic vinyl compound monomer unit.  9. A rubber latex composition for producing a foam, comprising a latex of a conjugated polymer rubber, a vulcanization system and, if necessary, a gelling agent,  The latex of the conjugated polymer rubber is represented by the following formula (1):  (HS-Ri-M-) n-R2 (1) [In equation (1), oo  II II  M represents -C-O- or -S-O-,  II  O  Is an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may have a substituent (the aliphatic hydrocarbon group has a propyloxyl group as a substituent when M is -CO-〇-) Or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent, n is when M is -CO-0-:! Integer of ~ 6, M is - S_〇 ₃ - 1 when represent respectively, R2 is when n = l, a hydrogen atom, an alkali metal, - NR ₄ (. R is independently representing a hydrogen atom or an alkyl or hydroxyalkyl group having 1-8 carbon atoms), a carbon number 1 to 1 5 Represents an alkyl group or an alkoxyalkyl group having 2 to 8 carbon atoms, When n = 2 to 6, it represents a hydrocarbon group having 2 to 18 carbon atoms or a heterocyclic ring having 2 to 5 carbon atoms. However, when n = 2, R ² may be an alkaline earth metal. ] A rubber latex composition for producing a foam, characterized in that at least one thiol compound represented by the formula is a latex of a conjugated gen-based polymer rubber bonded to the polymer rubber molecule via the thiol group.  10 0.1 to 10 parts by weight of sulfur based on 100 parts by weight of a conjugated polymer rubber (solid content) to which at least one thiol compound represented by the formula (1) is bonded. 10. The rubber latex composition for producing a foam according to claim 9, which comprises 0.5 to 10 parts by weight of zinc white and 0.1 to 5 parts by weight of a vulcanization accelerator.  1 1. The addition rate of at least one thiol compound represented by the formula (1) to the conjugated polymer rubber is 0 per 100 double bonds of the conjugated monomer unit in the polymer rubber. The rubber latex composition for producing a foam according to claim 9 or 10, wherein the amount is 1 to 15 mol. 1 2. Conjugated gen system of at least one thiol compound represented by formula (1) The foam according to claim 9 or 10, wherein the addition rate to the polymer rubber is 1 to 10 mol per 100 double bonds of the conjugated gen monomer units in the polymer rubber. Rubber latex composition for body production.  1 3. A foam obtained by foaming and vulcanizing a rubber composition containing a latex of a conjugated polymer rubber, a vulcanization system and, if necessary, a gelling agent,  The latex of the conjugated polymer rubber is represented by the following formula (1): (HS-Ri-M-) _n -R2 (1)  [In equation (1),  o o  II II  M represents -C-〇- or -S-0-,  II O  Ri is an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may have a substituent (the aliphatic hydrocarbon group has a lipoxyl group as a substituent when M is -CO-0-); Or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent, n, when M is -CO-0- :! Integer of ~ 6, M is - S_〇 ₃ - 1 when represent respectively,  R2 is, when n == l, a hydrogen atom, an alkali metal, -NR4 (R independently represents a hydrogen atom or an alkyl or hydroxyalkyl group having 1 to 8 carbon atoms.), And having 1 to 15 carbon atoms. Represents an alkyl group or an alkoxyalkyl group having 2 to 8 carbon atoms, When n = 2 to 6, it represents a hydrocarbon group having 2 to 18 carbon atoms or a heterocyclic group having 2 to 5 carbon atoms. However, when n = 2, R ² may be an alkaline earth metal. ] A rubber foam characterized in that at least one thiol compound represented by the formula is a latex of a conjugated gen-based polymer rubber bonded to the polymer rubber molecule via the thiol group.