WO2018174068A1

WO2018174068A1 - Laminated article

Info

Publication number: WO2018174068A1
Application number: PCT/JP2018/011105
Authority: WO
Inventors: 健太郎早坂; 実紗山本; 伊賀　隆志
Original assignee: 日本ゼオン株式会社
Priority date: 2017-03-23
Filing date: 2018-03-20
Publication date: 2018-09-27
Also published as: JPWO2018174068A1

Abstract

A laminated article provided with a substrate and a polymer layer formed from polymer latex, wherein: the polymer layer covers the substrate in a state in which part of the polymer layer has infiltrated the substrate; the ratio (t1/t2) of the thickness t1 of an infiltration polymer layer, which is the portion of the polymer layer that infiltrates the substrate, with respect to the thickness t2 of a surface polymer layer, which is the portion of the polymer layer that covers the substrate, is 0.15-5.0, where t1 is the thickness of the infiltration polymer layer from the surface of the substrate, and t2 is the thickness of the surface polymer layer from the surface of the substrate; and the Young's modulus of the portion of the substrate on which the polymer layer is laminated is 800 kPa or less.

Description

Laminated body

The present invention relates to a laminate comprising a substrate and a polymer layer formed from a polymer latex. Moreover, this invention relates also to the method for measuring the softness | flexibility of such a laminated body and the film forming body for forming such a laminated body.

Conventionally, by covering fiber gloves with rubber or resin for various purposes such as factory manufacturing, light work, construction work, and farm work, solvent resistance, grip properties, wear resistance, etc. are improved. Protective gloves are used.

Since such protective gloves are usually used in contact with the human body, in addition to being excellent in mechanical strength and durability such as wear resistance, it is required to have excellent flexibility. It has been.

On the other hand, it is difficult to quantitatively measure the flexibility of such a protective glove. Therefore, in order to evaluate the flexibility, a glove-shaped sample is actually made and actually used by a plurality of subjects. It is necessary to check the feeling of use (softness) by having the wearer wear it and perform light work, and there is a problem that it takes time and effort to evaluate flexibility.

On the other hand, for example, in Patent Document 1, a sample is taken from a protective glove, and the flexibility is evaluated by measuring the bending rigidity of the collected sample using a bending tester. Thus, it was difficult to say that the softness was appropriately evaluated because the correlation between the results and the feeling of use (softness) when actually worn was low. Therefore, in the past, there was a situation in which the flexibility cannot be properly evaluated for a thin sample such as a laminate such as a protective glove, so what kind of laminate would be excellent in flexibility. It has not been clarified whether it will be a product, and it has been difficult to produce a laminate having excellent flexibility.

International Publication No. 2012/070576

The present invention has been made in view of such a situation, and an object thereof is to provide a laminate having excellent flexibility.

As a result of intensive studies to achieve the above object, the present inventors have permeated the substrate out of the polymer layers in a laminate comprising a substrate and a polymer layer formed from a polymer latex. The thickness of the portion and the thickness of the portion of the polymer layer that covers the surface of the base material are controlled so as to be in a predetermined state, and the laminate in the portion where the polymer layer is laminated on the base material The inventors have found that the above-described object can be achieved by controlling the Young's modulus within a specific range, and have completed the present invention.

That is, according to the present invention, a laminate comprising a substrate and a polymer layer formed from a polymer latex, wherein the polymer layer partially penetrates the substrate. A portion of the polymer layer that coats the base material and is a portion of the polymer layer that penetrates the base material, where the thickness from the surface of the base material is t ₁ and covers the base material The ratio of the thickness t ₁ of the osmotic polymer layer to the thickness t ₂ of the surface polymer layer (t ₁ / t) where t ₂ is the thickness of the surface polymer layer from the surface of the substrate. ₂ ) is 0.15 to 5.0, and a laminate having a Young's modulus of 800 kPa or less at a portion where the polymer layer is laminated on the substrate is provided.

In the laminate of the present invention, the thickness t ₁ of the osmotic polymer layer is preferably 0.05 to 0.6 mm.
In the laminate of the present invention, the polymer latex for forming the polymer layer has a Young's modulus of the film molded body of 10,000 kPa or less when the volatile matter is removed to form a film molded body. preferable.
In the laminate of the present invention, the polymer latex for forming the polymer layer contains a conjugated diene rubber having a conjugated diene monomer unit content of 52 to 78% by weight as the polymer. Is preferred.
In the laminate of the present invention, the polymer latex for forming the polymer layer is a conjugated polymer in which the content of the α, β-ethylenically unsaturated nitrile monomer unit is 20 to 40% by weight. It is preferable to contain a diene rubber.
In the laminate of the present invention, the polymer latex for forming the polymer layer is a conjugated diene-based polymer having a carboxyl group-containing ethylenically unsaturated monomer unit content of 2 to 10% by weight as the polymer. It is preferable to contain rubber.

Further, in the present invention, a method for measuring the flexibility of a rubber film molded body or a laminate having a rubber layer, wherein an indenter is pushed into the film molded body or the laminated body with a predetermined pushing load, Provided is a method for measuring the flexibility of a rubber film molded body or a laminate having a rubber layer, in which the flexibility is measured based on the indentation load and the displacement due to the indentation when the indenter is indented.
In the measurement method of the present invention, it is preferable to measure flexibility based on the indentation load and the displacement due to the indentation when the indenter is indented with a plurality of different indentation loads.
In the measurement method of the present invention, it is preferable to determine the Young's modulus of the film molded body or the laminate based on the indentation load when the indenter is indented and the displacement due to the indentation.
In the measurement method of the present invention, it is preferable that the film molded body or the laminated body is used in contact with a human body.

According to the present invention, a laminate having excellent flexibility can be provided.

FIG. 1 (A) is a cross-sectional view of a fiber base material before forming a polymer layer, and FIG. 1 (B) is formed by laminating a polymer layer on the fiber base material shown in FIG. 1 (A). It is sectional drawing of a laminated body. FIG. 2 is a diagram illustrating an example of an indentation test apparatus 20 that can be used in the measurement method of the present invention. FIG. 3 is a characteristic curve showing the relationship between the indentation load on the measurement sample 10 and the displacement caused by the indentation of the measurement sample 10. FIG. 4 is a graph plotting the measurement results of the Young's modulus of the film molded body and the Young's modulus of the protective gloves in association with the results of the sensory test. FIG. 5 is a graph plotting Young's modulus and bending test results in association with sensory test results.

The laminate of the present invention is a laminate comprising a substrate and a polymer layer formed from a polymer latex,
The polymer layer partially covers the base material in a state of permeating the base material,
Wherein one of the polymer layers, which is a penetration portion to the substrate osmopolymers layer, the thickness from the surface of the substrate and t _1, the surface polymer layer is a portion that covers the substrate, When the thickness from the surface of the base material is t ₂ , the ratio of the thickness t ₁ of the osmotic polymer layer to the thickness t ₂ of the surface polymer layer (t ₁ / t ₂ ) is 0.15 to 5.0,
The Young's modulus in the portion where the polymer layer is laminated on the base material is 800 kPa or less.

<Laminated body>
The laminate of the present invention comprises a substrate and a polymer layer. Although the laminated body of this invention can be used for the use for which a softness | flexibility is required and it does not specifically limit, For example, a laminated body provided with a fiber base material and a polymer layer using a fiber base material as a base material. It is preferably used as a work glove, particularly a protective glove for home use, agriculture use, fishery use, industrial use and the like used in contact with the human body.
Below, as a laminated body which has a polymer layer, the laminated body which has a fiber base material and polymer layer used in contact with human bodies, such as a protective glove, is illustrated and demonstrated.

The fiber base material is not particularly limited as long as it is made of fiber, but natural fibers such as cotton, wool, hemp, and wool, and synthetic fibers such as polyester, polyurethane, acrylic, and nylon may be used as a material. Among these, nylon is preferably used. The fiber base material may be knitted or sewn, and may be a woven fabric or a non-woven fabric.

The thickness of the fiber base material (base material layer average thickness d of the fiber base material described later) is not particularly limited, but is preferably 0.05 to 3.00 mm, more preferably 0.10 to 2.00 mm, and still more preferably. 0.15 to 1.5 mm. The linear density of the fiber base material is not particularly limited, but is preferably 50 to 500 denier. The gauge number of the fiber base material is not particularly limited, but is preferably 7 to 18 gauge. Here, the number of gauges refers to the number of knitting machine needles between 1 inch.

In the laminate of the present invention, for example, after a coagulant solution is adhered to such a fiber substrate, a polymer latex containing a polymer is brought into contact with the fiber substrate to which the coagulant solution is adhered. It can be obtained by solidifying the polymer in the combined latex to form a polymer layer on the fiber substrate. In this case, the coagulant solution adhering to the fiber base material penetrates between the fibers constituting the fiber base material. In this state, when the polymer latex is brought into contact with the fiber base material into which the coagulant solution has permeated, a part of the polymer latex penetrates between the fibers constituting the fiber base material, and the polymer inside is solidified. By doing so, as shown in FIG. 1 (A) and FIG. 1 (B), a polymer layer is formed on the surface of the fiber substrate, and a part of the polymer layer constitutes the fiber substrate. It penetrates to the gap between the fibers. 1A is a cross-sectional view of the fiber base material before forming the polymer layer, and FIG. 1B is a view in which the polymer layer is laminated on the fiber base material shown in FIG. It is sectional drawing of the laminated body formed.
In addition, the polymer layer formed by coagulating the polymer in the polymer latex may have a multilayer laminated structure by performing the above method a plurality of times.

In the laminate shown in FIG. 1 (B), the polymer layer covers the fiber base material in a state where a part of the polymer layer penetrates between the fibers constituting the fiber base material. Moreover, in FIG. 1 (B), the part which permeate | transmitted the clearance gap between the fibers from the surface of a fiber base material among the polymer layers which comprise a laminated body is made into a permeation | polymerization polymer layer, and fiber is used among polymer layers. The part which coat | covers a fiber base material from the surface of a base material is shown as a surface polymer layer. In the following description, the polymer layer will be described as appropriately consisting of a osmotic polymer layer and a surface polymer layer. Usually, the osmotic polymer layer and the surface polymer layer are integrally formed. It becomes.

In the laminate of the present invention, the ratio of the thickness t ₁ of the osmotic polymer layer to the thickness t ₂ of the surface polymer layer (t ₁ / t ₂ ) may be 0.15 to 5.0, and the durability From the viewpoint of highly balancing flexibility and comfort when worn, it is preferably 0.2 to 0.5, more preferably 0.25 to 4.80, and still more preferably 0.30 to 4.60. The thickness t ₁ of the penetrating polymer layer is preferably 0.05 to 0.6 mm, more preferably 0.10 to 0.00 mm, from the viewpoint of durability when the laminate is used as a protective glove or the like. It is 55 mm, more preferably 0.10 to 0.50 mm. By setting the thickness t ₁ of the osmotic polymer layer within the above range, durability when the laminate is used as a protective glove or the like can be more appropriately increased. The thickness t ₂ of the surface polymer layer is preferably 0.01 to 3.00 mm, more preferably 0.02 to 2.5 mm, from the viewpoint of durability when the laminate is used as a protective glove or the like. More preferably, it is 0.03 to 2.0 mm.

Further, the thickness of the osmotic polymer layer with respect to the average thickness d of the base material layer of the fiber base material from the viewpoint of highly balancing the durability, flexibility, and comfort during wearing when the laminate is used as a protective glove or the like. the ratio of _t ₁ _(t ₁ / d) is preferably 0.1 to 0.95, and more preferably from 0.1 to 0.9 and more preferably 0.15 to 0.8. The total thickness of the laminate (total of the surface polymer layer thickness t ₂ and the fiber substrate base layer average thickness d) is preferably 0.75 to 3.70 mm, more preferably 0.75. ~ 3.5 mm. In the microstructure of the fiber base, the thickness may be different between the portion where the fiber overlap is dense and the portion where the fiber overlap is sparse. The base material layer average thickness d of a base material shall be calculated | required as the average value which made the thickness of the part with which the overlapping degree of a fiber is dense about the fiber base material the thickness.

The polymer constituting the polymer latex used for obtaining the laminate of the present invention is not particularly limited. Natural rubber; conjugated diene rubber obtained by polymerizing or copolymerizing conjugated dienes such as butadiene and isoprene Among these, conjugated diene rubbers are preferable. Examples of the conjugated diene rubber include so-called nitrile rubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber and the like obtained by copolymerizing nitrile, and among these, nitrile rubber is particularly preferable.

The nitrile rubber is not particularly limited, and a nitrile rubber obtained by copolymerizing an α, β-ethylenically unsaturated nitrile monomer and other copolymerizable monomers used as necessary can be used.

The α, β-ethylenically unsaturated nitrile monomer is not particularly limited, and an ethylenically unsaturated compound having a nitrile group and preferably having 3 to 18 carbon atoms can be used. Examples of such α, β-ethylenically unsaturated nitrile monomers include acrylonitrile, methacrylonitrile, halogen-substituted acrylonitrile and the like, and among these, acrylonitrile is particularly preferable. These α, β-ethylenically unsaturated nitrile monomers may be used alone or in combination of two or more.

The content of the α, β-ethylenically unsaturated nitrile monomer unit in the nitrile rubber is preferably 10 to 45% by weight, more preferably 20 to 40% by weight, still more preferably based on the total monomer units. It is 21 to 38% by weight, particularly preferably 22 to 37% by weight. By setting the content ratio of the α, β-ethylenically unsaturated nitrile monomer unit within the above range, the laminate can be excellent in solvent resistance and in texture.

Further, as a nitrile rubber, a conjugated diene monomer unit is provided from the viewpoint of imparting rubber elasticity and more effectively preventing cracks from occurring in the polymer layer of the obtained laminate. The thing containing is preferable. Examples of the conjugated diene monomer forming the conjugated diene monomer unit include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, chloroprene and the like having 4 to 4 carbon atoms. 6 conjugated diene monomers are preferred, 1,3-butadiene and isoprene are more preferred, and 1,3-butadiene is particularly preferred. In addition, these conjugated diene monomers may be used individually by 1 type, and may be used in combination of 2 or more type.

The content ratio of the conjugated diene monomer unit is preferably 40 to 80% by weight, more preferably 52 to 78% by weight, still more preferably 54 to 76% by weight, based on all monomer units constituting the nitrile rubber. Particularly preferred is 56 to 74% by weight. By making the content rate of a conjugated diene monomer unit into the said range, a laminated body can be made excellent in solvent resistance and excellent in texture.

Nitrile rubber is also a monomer that forms α, β-ethylenically unsaturated nitrile monomer units and other ethylenically unsaturated monomers that are copolymerizable with monomers that form conjugated diene monomer units. An acid monomer may be included.

Such other copolymerizable ethylenically unsaturated acid monomer is not particularly limited, and examples thereof include a carboxyl group-containing ethylenically unsaturated monomer, a sulfonic acid group-containing ethylenically unsaturated monomer, Examples thereof include phosphoric acid group-containing ethylenically unsaturated monomers.

The carboxyl group-containing ethylenically unsaturated monomer is not particularly limited, but ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; fumaric acid, maleic acid, itaconic acid, maleic anhydride, anhydrous And ethylenically unsaturated polyvalent carboxylic acids such as itaconic acid and anhydrides thereof; partially esterified products of ethylenically unsaturated polyvalent carboxylic acids such as methyl maleate and methyl itaconic acid; and the like.

The sulfonic acid group-containing ethylenically unsaturated monomer is not particularly limited, but vinyl sulfonic acid, methyl vinyl sulfonic acid, styrene sulfonic acid, (meth) allyl sulfonic acid, (meth) acrylic acid-2-sulfonic acid ethyl And 2-acrylamido-2-hydroxypropanesulfonic acid.

The phosphoric acid group-containing ethylenically unsaturated monomer is not particularly limited, but includes (meth) acrylic acid-3-chloro-2-propyl phosphate, (meth) acrylic acid-2-ethyl phosphate, 3-allyloxy. Examples include -2-hydroxypropane phosphoric acid.

These other copolymerizable ethylenically unsaturated acid monomers can also be used as alkali metal salts or ammonium salts, and can be used alone or in combination of two or more. . Among the other copolymerizable ethylenically unsaturated acid monomers, carboxyl group-containing ethylenically unsaturated monomers are preferable, ethylenically unsaturated monocarboxylic acids are more preferable, and methacrylic acid is particularly preferable.

The content ratio of the ethylenically unsaturated acid monomer unit is preferably 2 to 10% by weight, more preferably 2.5 to 9.0% by weight, and still more preferably 3.0 to 8.0% by weight. .

The polymer latex can be obtained, for example, by emulsion polymerization of a monomer mixture containing the above monomers. In the emulsion polymerization, commonly used polymerization auxiliary materials such as an emulsifier, a polymerization initiator, and a molecular weight modifier can be used.

In addition, as the polymer latex used for obtaining the laminate of the present invention, a film in the case of forming a film molded body by removing volatile components from the viewpoint that a laminate having excellent flexibility can be suitably obtained. It is preferable to use a molded product having a Young's modulus of 10,000 kPa or less. In this case, the Young's modulus of the film molded body may be 10,000 kPa or less, preferably 9,500 kPa or less, more preferably 9,000 kPa or less, further preferably 8,000 kPa or less, and particularly preferably 7, 000 kPa or less. By setting the Young's modulus within the above range, the flexibility of the obtained laminate can be more appropriately increased. The lower limit of the Young's modulus of the film molded body is not particularly limited, but is usually 0.01 kPa or more, preferably 0.02 kPa or more.

As a method for controlling the Young's modulus within the above range when using a polymer latex having a Young's modulus of 10,000 kPa or less when removing a volatile component to form a film molded product, as a polymer latex, Although it does not specifically limit, The method of adjusting the kind and composition of a polymer which comprise polymer latex in the above-mentioned range, The method of adjusting the kind and quantity of a thickener added to polymer latex, etc. are mentioned.

For example, when the polymer latex is a conjugated diene rubber latex, the α, β-ethylenically unsaturated nitrile monomer unit is preferably 20 to 40% by weight, more preferably 21 to 38% by weight, More preferably, it is contained in the range of 22 to 37% by weight, and the conjugated diene monomer unit is preferably 52 to 78% by weight, more preferably 54 to 76% by weight, still more preferably 56 to 74% by weight. In addition to these, the unit of the carboxyl group-containing ethylenically unsaturated monomer is preferably 2 to 10% by weight, more preferably 2.5 to 9.0% by weight. Further, it is particularly preferable to contain in the range of 3.0 to 8.0% by weight. In this case, as the monomer constituting each monomer unit, those described above can be used.

By setting the content ratio of the α, β-ethylenically unsaturated nitrile monomer unit in the above range, the Young's modulus in the case of forming a film molded body by removing volatile matter can be further reduced. The softness | flexibility of the laminated body obtained can be improved more appropriately. Moreover, by making the content rate of a conjugated diene monomer unit into the said range, it can suppress more effectively that a gel generate | occur | produces in polymer latex, and, thereby, a polymer is made by polymer latex. When the layer is formed, the polymer layer is prevented from becoming a non-uniform film due to the generation of such a gel, and cracks are generated in the polymer layer of the obtained laminate. This can be more effectively prevented, the appearance can be improved, and the laminate can be excellent in solvent resistance and texture. Furthermore, by including the unit of the carboxyl group-containing ethylenically unsaturated monomer in the above content ratio, the Young's modulus in the case of forming a film molded body by removing the volatile matter can be further reduced. Thus, the flexibility of the obtained laminate can be improved more appropriately.

Further, as the polymer latex, a polymer constituting the polymer latex having a methylethylketone insoluble content is preferably 90% by weight or less, more preferably 85% by weight or less, and further preferably 80% by weight or less. Is preferred. By making the methyl ethyl ketone insoluble content in the above range, it is possible to more effectively suppress the occurrence of gel in the polymer latex, and thereby, when the polymer layer is formed with the polymer latex, The polymer layer is prevented from becoming a non-uniform film due to the occurrence of such a gel, and the resulting laminate is more effectively prevented from cracking in the polymer layer. And the appearance can be improved. In addition, the amount insoluble in methyl ethyl ketone can be measured, for example, by the following method. That is, first, a polymer film contained in the polymer latex is obtained, and the weight (W1) of the dried film before being immersed in methyl ethyl ketone is measured, and the film is placed in an 80-mesh cage net. And immersed in methyl ethyl ketone for 24 hours at room temperature. Next, the dried film is obtained by drying the immersed film at 105 ° C. to obtain a dried film, and the weight (W2) of the dried film after the immersion is measured. And based on the obtained measurement result, it is computable by a following formula.
Methyl ethyl ketone insoluble content (unit:% by weight) = (weight of dry film after immersion (W2) / weight of dry film before immersion (W1)) × 100

Further, as the polymer latex, a latex blended with a compounding agent such as a crosslinking agent or a thickener may be used. That is, as polymer latex, you may mix | blend compounding agents, such as a crosslinking agent and a thickener, and may use it as a composition of a latex. In this case, when a polymer latex having a Young's modulus of 10,000 kPa or less in the case of using a film molded body by removing volatile components as the polymer latex, The Young's modulus of the film molded body in the case where the film molded body is removed to form a film molded body may be 10,000 kPa or less.

As the crosslinking agent, it is preferable to use a sulfur-based crosslinking agent. Although it does not specifically limit as a sulfur type crosslinking agent, Sulfur, such as powder sulfur, sulfur white, precipitation sulfur, colloidal sulfur, surface treatment sulfur, insoluble sulfur; sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, dibenzothia Sulfur-containing compounds such as zildisulfide, caprolactam disulfide, phosphorus-containing polysulfide, and polymer polysulfides; sulfur-donating compounds such as tetramethylthiuram disulfide, selenium dimethyldithiocarbamate, and 2- (4′-morpholinodithio) benzothiazole; Is mentioned. These crosslinking agents may be used alone or in combination of two or more.

Moreover, when using sulfur as a crosslinking agent, it is preferable to use together a crosslinking accelerator (vulcanization accelerator) and zinc oxide.
The crosslinking accelerator (vulcanization accelerator) is not particularly limited. For example, dithiocarbamine such as diethyldithiocarbamic acid, dibutyldithiocarbamic acid, di-2-ethylhexyldithiocarbamic acid, dicyclohexyldithiocarbamic acid, diphenyldithiocarbamic acid, and dibenzyldithiocarbamic acid. Acids and their zinc salts; 2-mercaptobenzothiazole, 2-mercaptobenzothiazole zinc, 2-mercaptothiazoline, dibenzothiazyl disulfide, 2- (2,4-dinitrophenylthio) benzothiazole, 2- (N, N-diethylthio-carbylthio) benzothiazole, 2- (2,6-dimethyl-4-morpholinothio) benzothiazole, 4-morpholinyl-2-benzothiazyl disulfide, 1,3 Bis (2-benzothiazyl mercaptomethyl) such as urea. Among these, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, 2-mercaptobenzothiazole, 2-mercaptobenzothiazole zinc is preferred. These crosslinking accelerators may be used alone or in combination of two or more.

Further, the viscosity of the polymer latex may be adjusted so that a thickener is added from the viewpoint of controlling the thickness t ₁ of the penetrating polymer layer and the thickness t ₂ of the surface polymer layer. Good. Although it does not specifically limit as a thickener, For example, Vinyl compounds, such as polyvinyl alcohol and polyvinyl pyrrolidone; Cellulose derivatives, such as hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethylcellulose salt; Polycarboxylic acid compound and its sodium salt; Polyethylene And polyoxyethylene derivatives such as glycol ethers.

When a thickener is blended in the polymer latex, the 1% viscosity of the thickener used is preferably 20 mPa · s or more, more preferably 50 mPa · s or more, and even more preferably 200 mPa · s or more. The 1% viscosity of the thickener is obtained by dissolving the thickener in water to obtain an aqueous solution having a concentration of 1% by weight, and measuring the viscosity at 25 ° C. using a B-type viscometer at a rotation speed of 10 rpm. Can be obtained. By setting the 1% viscosity of the thickener within the above range, a gel is generated in the polymer latex, and due to this gel, particles are generated on the surface of the polymer layer of the resulting laminate. It is possible to more effectively suppress the appearance defect due to the above, and the amount of the thickener used can be reduced, so that the amount of the thickener used is increased. Curing of the polymer layer can be suppressed more effectively.

In addition, when a thickener is blended in the polymer latex, the particle size of the insoluble component when the thickener to be used is dissolved in water is preferably 30 μm or less, more preferably 28 μm or less, and still more preferably 25 μm or less. By setting the particle size of the insoluble component of the thickener in the above range, it is possible to more effectively suppress poor appearance due to generation of particles on the surface of the polymer layer of the obtained laminate. Become.

When a thickener is blended in the polymer latex, the content of the thickener in the polymer latex is preferably 0.1 to 5.0% by weight, more preferably 0.1 to 4.0% by weight. %, And further 0.1 to 3.0% by weight. By making the content rate of a thickener into the said range, the viscosity of polymer latex can be made more moderate.

The method of adding the polymer latex to the thickener is not particularly limited, but when a polymer latex to which a crosslinking agent is added is used, it is prevented that aggregates are generated in the polymer latex. From the viewpoint of enabling better transfer of the polymer latex, a method of adding a thickener after aging the polymer latex, or a portion of the thickener before aging the polymer latex It is preferable to use a method in which a thickener is further added after aging, and a method in which a thickener is added after aging of the polymer latex is particularly preferable.

Although it does not specifically limit as a method to manufacture the laminated body of this invention, For example, the following methods can be used.
That is, in a laminate having a fiber base material and a polymer layer, for example, a coagulant solution is attached to the fiber base material, and then a polymer latex is brought into contact with the fiber base material to which the coagulant solution is attached. The method of obtaining the laminated body which consists of a fiber base material and a polymer layer by forming a polymer layer on a fiber base material by coagulating a polymer can be used. Moreover, the multilayer structure laminated | stacked several times after polymer layer formation may be sufficient. The method for attaching the polymer latex to the fiber substrate is not particularly limited, and examples thereof include a method of immersing the fiber substrate in the polymer latex.

In addition, when attaching the coagulant solution to the fiber base material, it is preferable to immerse the fiber base material in the coagulant solution in a state where the fiber base material is previously covered with a molding die of a desired shape, It is preferable to immerse the polymer latex in the fiber base material to which the coagulant solution is attached. Although it does not specifically limit as a shaping | molding type | mold which covers a fiber base material, Various things, such as a product made from porcelain, glass, metal, and plastics, can be used. The shape of the molding die may be a desired shape according to the shape of the final product. For example, when the laminate having a polymer layer is a protective glove, the mold for various gloves, such as a mold having a shape from the wrist to the fingertip, is used as a mold for covering the fiber substrate. Is preferably used.

It is preferable to remove the solvent contained in the coagulant solution by attaching the coagulant solution to the fiber substrate and then drying. The drying temperature at this time is not particularly limited and may be selected according to the solvent to be used, but is preferably 10 to 80 ° C., more preferably 15 to 70 ° C. The drying time is not particularly limited, but is preferably 1 to 600 seconds, more preferably 5 to 300 seconds.

Next, the polymer latex is brought into contact with the fiber base material to which the coagulant solution is adhered in this manner, so that the polymer in the polymer latex is coagulated to form a polymer layer on the fiber base material. .

The method of bringing the polymer latex into contact with the fiber base material to which the coagulant solution is attached is not particularly limited, and examples thereof include a method in which the fiber base material to which the coagulant solution is attached is immersed in the polymer latex.

In addition, when the fiber base material to which the coagulant solution is attached is immersed in the polymer latex, the fiber base material to which the coagulant solution is attached is put on the polymer latex in a state where the fiber base material is put on a molding die having a desired shape. It is preferable to immerse. In this case, the fiber base material is coated with the coagulant solution as described above in a state where the fiber base material is previously covered with a molding die having a desired shape, and then the coagulant solution is adhered to the fiber base material. Is preferably immersed in a polymer latex while being covered with a molding die. In addition, when using what added the crosslinking agent as polymer latex, you may use what was age | cured previously (it is also called pre-vulcanization) as polymer latex.

Further, it is preferable to perform drying after immersing the fiber substrate to which the coagulant solution is adhered in the polymer latex. The drying temperature at this time is not particularly limited, but is preferably 10 to 80 ° C., more preferably 15 to 80 ° C. The drying time is not particularly limited, but is preferably 5 seconds to 120 minutes, more preferably 10 seconds to 60 minutes.

Furthermore, the fiber base material may be dipped in polymer latex and dried, and then polymer latex may be further dipped and laminated multiple times.

In addition, when a crosslinking agent is blended in the polymer latex, it may be crosslinked by heating as necessary.

Furthermore, when the polymer layer is formed in a state where the fiber base material is put on the molding die, the laminate is obtained by detaching the fiber base material on which the polymer layer is formed from the molding die. Can do. As the desorption method, it is possible to adopt a method of peeling from the mold by hand, or peeling by water pressure or compressed air pressure.
Thus, the laminated body which has a fiber base material and a polymer layer as an example of the laminated body which has a polymer layer can be obtained.

The laminate of the present invention measures the Young's modulus at the portion where the polymer layer is laminated on the substrate (that is, the measurement is performed on the substrate and the polymer layer at the place where the polymer layer is laminated on the substrate). The Young's modulus obtained by carrying out is 800 kPa or less, preferably 750 kPa or less, more preferably 700 kPa or less, further preferably 600 kPa or less, and particularly preferably 500 kPa or less. By setting the Young's modulus within the above range, the obtained laminate can be remarkably excellent in flexibility when used as protective gloves or the like. In addition, the lower limit of the Young's modulus in the part of the laminate in which the polymer layer is laminated on the base material is not particularly limited, but is usually 0.01 kPa or more, preferably 0.02 kPa or more.

In particular, in the past, there was a situation where flexibility could not be properly evaluated for thin samples such as laminates such as protective gloves. It was in a situation where it was not made clear what would happen. On the other hand, the present inventors have found a method that can appropriately measure the Young's modulus for a thin sample such as a laminated body such as a protective glove by a method described later, and in this way. The Young's modulus measured in this way was found to be highly correlated with the flexibility of the laminate. Based on such knowledge, the present invention obtains a laminate that is remarkably excellent in flexibility by controlling the Young's modulus of the laminate in which the polymer layer is laminated on the base material within the above range. It is something that can be done.

In the laminate of the present invention, the method of controlling the Young's modulus in the portion where the polymer layer is laminated on the base material within the above range is not particularly limited, but the type and composition of the polymer constituting the polymer latex are not limited. The method of adjusting, the method of adjusting the type and amount of the thickener added to the polymer latex, and the ratio of the thickness t ₁ of the osmotic polymer layer to the thickness t ₂ of the surface polymer layer (t ₁ / t ₂ ) Examples of the method include controlling each of the above ranges. In addition, a method using a polymer latex having a Young's modulus of 10,000 kPa or less in the case of forming a film molded body by removing volatile components is also suitable.

<Measurement method of Young's modulus>
Next, a method for measuring the Young's modulus of the laminate of the present invention will be described.
The Young's modulus of the laminate of the present invention is measured based on the indentation load and the displacement due to indentation when the indenter is pushed into the laminate having a polymer layer with a predetermined indentation load. be able to. Since the Young's modulus measured by this method serves as an index indicating flexibility, according to this method, the flexibility of a laminate having a rubber layer such as the laminate of the present invention can be measured.

In the following, the method for measuring the Young's modulus of the laminate of the present invention will be described. However, the Young's modulus of the film molded body obtained using the polymer latex (that is, the film molded body obtained using the polymer latex, etc.) The flexibility of the rubber film molding can also be measured in the same manner.

In the measurement of the Young's modulus of the present invention, the indenter is pushed with at least one indentation load into the laminate having the polymer layer, and when the indenter is indented with at least one indentation load. It is sufficient to measure the Young's modulus based on the displacement, but from the viewpoint that the Young's modulus can be measured more appropriately, the indentation load when the indenter is pushed in with different indentations and indented with different indentations It is preferable to measure the Young's modulus based on the corresponding displacement due to the pressing.

FIG. 2 is a diagram showing an example of an indentation test apparatus 20 that can be used for measuring Young's modulus. In the following, the measurement method of Young's modulus in the case of using the indentation test apparatus 20 shown in FIG. 2 will be described as an example. The measurement method of Young's modulus is a method using the indentation test apparatus 20 shown in FIG. It is not particularly limited.

The indentation test apparatus 20 shown in FIG. 2 includes a suction table 30 for placing a measurement sample 10 to be measured for Young's modulus on a measurement table 21, and above the measurement table 21 and the suction table 30. A support arm 22 that holds the spherical indenter 29 is provided. Further, the support arm 22 is provided with a horizontal arm 23, and the spherical indenter 29 is moved in the in-plane direction of the measurement table 21 and the suction table 30 by the horizontal drive mechanism provided in the horizontal arm 23, that is, in the drawing. Are movable in the X direction and the Y direction (direction perpendicular to the paper surface). Accordingly, the indentation test apparatus 20 can perform tests on various portions of the measurement sample 10.

In the indentation test apparatus 20, a stage 26 is provided so as to be movable in the Z direction in the figure via a coarse moving vertical moving mechanism 24 and a fine moving vertical moving mechanism 25. A spherical indenter 29 is connected to the stage 26 via a load cell 27 and a load shaft 28. The coarse movement vertical movable mechanism 24 can be provided with a movable mechanism using a ball nut, for example, and the stage 26 can be moved in the Z direction in the figure by the rotation of the motor. Further, the fine moving vertical moving mechanism 25 can be provided with a voice coil motor as a moving mechanism, for example, and the stage 26 can be moved in the Z direction with a fine pitch with high accuracy.

According to the indentation test apparatus 20, after the spherical indenter 29 is brought close to the measurement sample 10 by the coarse moving vertical movable mechanism 24 via the stage 17, the spherical indenter 29 is moved by the fine moving vertical movable mechanism 25 via the stage 26. The indenter 29 can be pushed into the measurement sample 10 with a fine pitch with high accuracy. Further, the indentation load at this time can be detected by the load cell 27. Further, the fine movement vertical movable mechanism 25 includes, for example, an optical position detection mechanism using a laser, and the like, and thereby, with a high degree of accuracy, the amount of pressing with respect to the measurement sample 10, that is, the displacement due to the pressing of the measurement sample 10. (Displacement in the thickness direction) can be detected.

Then, a specific measurement method using such an indentation test apparatus 20 will be described. First, for a laminate to be measured for Young's modulus, a portion where a polymer layer is laminated on a base material is necessary. Accordingly, the sample 10 is processed to an appropriate size, and the sample 10 is placed on the suction table 30. The suction table 30 has a plurality of suction holes formed in the vicinity of a measurement location (that is, a location where the spherical indenter 29 abuts) on the surface thereof, and is connected to a suction pump (not shown). The measurement sample 10 can be fixed by suction from a plurality of suction holes. In the present invention, the measurement can be performed with high accuracy by performing the measurement while being fixed by suction. In particular, when the measurement is performed without fixing by suction, the laminated body that is the object of measurement often suffers from sagging of the sample during measurement and cannot be measured satisfactorily. On the other hand, by performing measurement while being fixed by suction, it is possible to effectively prevent the occurrence of such a defect, thereby realizing highly accurate measurement. When performing measurement of the laminate, in order to appropriately perform suction by the suction table 30, a resin tape is applied to a portion corresponding to the plurality of suction holes of the suction table 30 out of the surface opposite to the measurement surface. It is preferable that the measurement is performed by placing it on the suction table 30 after it is in a pasted state.

Next, the spherical indenter 29 is driven by the coarse moving vertical movable mechanism 24 through the stage 26, and the spherical indenter 29 is moved to the vicinity of the surface of the measurement sample 10 fixed on the suction table 30 by suction. Thereafter, the spherical indenter 29 is gradually pushed into the measurement sample 10 at a fine pitch through the stage 26 of the vertical moving mechanism 25 for fine movement, and the indentation load on the measurement sample 10 detected by the load cell 27 at this time, For example, the measurement sample as shown in FIG. 3 can be detected by continuously detecting the amount of pushing detected by the position detection mechanism provided in the fine moving vertical moving mechanism 25, that is, the displacement caused by the pushing of the measurement sample 10. A characteristic curve showing the relationship between the indentation load with respect to 10 and the displacement due to indentation of the measurement sample 10 can be obtained.

As specific measurement conditions, for example, a SUS product can be used as the spherical indenter 29, and the diameter is preferably 40 mm or less, more preferably 20 mm or less. The indentation speed during measurement is preferably 0.1 to 10 mm / s, more preferably 0.1 to 2 mm / s, and the maximum load in measurement is 0.5 to 50 N. Is preferable, and 0.5 to 20 N is more preferable.

Then, the Young's modulus of the measurement sample 10 can be obtained based on the characteristic curve showing the relationship between the indentation load on the measurement sample 10 shown in FIG. 3 and the displacement caused by the indentation of the measurement sample 10 obtained by the measurement. Hereinafter, a method for calculating the Young's modulus of the measurement sample 10 will be described.

First, when a sufficiently hard spherical indenter 29 is pushed into the measurement sample 10, the relationship between the pushing load F related to the pushing of the spherical indenter 29 and the pushing amount (that is, displacement of the measurement sample 10) δ is Hertz's. It is shown by the following formula (1) by the elastic contact theory.

In the above formulas (1) and (2), φ is the diameter of the spherical indenter 29, E is the Young's modulus of the measurement sample 10, and v is the Poisson's ratio of the measurement sample 10. In addition, α is a coefficient representing the flexibility of the measurement sample 10, and is hereinafter referred to as a flexibility coefficient.

Then, using the characteristic curve showing the relationship between the indentation load on the measurement sample 10 shown in FIG. 3 and the displacement due to the indentation of the measurement sample 10, the flexibility coefficient α can be obtained by the least square method or the like, The Young's modulus E of the measurement sample 10 can be obtained from the following equation (3) obtained by modifying the above equation (2).

On the other hand, the measurement sample 10 as a measurement object is the laminate of the present invention, and these are thin as described above. Therefore, when the spherical indenter 29 is pushed in, it is accompanied by pushing. Since the increase in the indentation load becomes significant, the above formula (1) based on the Hertz elastic contact theory cannot be applied with high accuracy in many cases. Therefore, when the thickness is thin like this, it is preferable to apply the following formula (4). By using such a formula (4), the pressing load F and the pressing amount related to the pressing of the spherical indenter 29 are used. (That is, the displacement of the measurement sample 10) δ can be expressed appropriately.

In the above equation (4), β is a coefficient representing the influence of the thinness of the measurement sample 10 on the load. Therefore, in the present invention, even when the measurement sample 10 is a thin sample like the laminate of the present invention, the indentation load on the measurement sample 10 shown in FIG. The coefficient β representing the influence on the load and the flexibility coefficient α can be obtained using the characteristic curve indicating the relationship with the displacement due to the pressing of the sample. Further, the Young of the measurement sample 10 can be obtained from the above equation (4). The rate E can be determined.

In the above description, the method for measuring the Young's modulus of the laminate of the present invention has been described. However, the Young's modulus of the film molded body in the case of forming a film molded body by removing volatile components as the polymer latex is 10,000 kPa. In the case of using the following, the above method may be used also when measuring the Young's modulus of the film molded body. That is, the volatile matter of the polymer latex is removed by a known method such as heating to obtain a film molded body, and the Young's modulus of the obtained film molded body may be measured according to the above method. The thickness of the film molded body produced here is a thickness that is difficult to measure the Young's modulus by the conventional method, specifically, usually 3.0 mm or less, preferably 2.5 mm or less. it can. Conventionally, the solid content obtained from the polymer latex can be measured as long as the solid content is in a bulk state, but the polymer latex is thin like a film molding. When used as a sample, it was difficult to measure the Young's modulus. On the other hand, according to the method of measuring the Young's modulus of the present invention described above, the Young's modulus can be measured even for a thin film molded body produced using a polymer latex.

According to the method of measuring the Young's modulus of the present invention described above, when the indenter is pushed in with a predetermined pushing load, the rubber film molded body or the laminate having the rubber layer to be measured, when the indenter is pushed in, Since the flexibility is measured based on the indentation load and the displacement caused by the indentation, the flexibility of the rubber film molded body or the laminate having the rubber layer can be appropriately measured. More specifically, the indenter Based on the indentation load and the displacement due to the indentation, the Young's modulus of the rubber film molded body or the laminate having the rubber layer is obtained. By using it as an index, the flexibility of a rubber film molded body or a laminate having a rubber layer can be appropriately measured.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the following, “part” is based on weight unless otherwise specified. Tests or evaluation methods for physical properties and characteristics are as follows.

Content measurement of butadiene units The content ratio of butadiene units was calculated by measuring the iodine value of nitrile rubber (according to JIS K 6235).

Content measurement of acrylonitrile unit The content ratio of the acrylonitrile unit was calculated by measuring the nitrogen content in the nitrile rubber by the Kjeldahl method according to JIS K6384.

Measurement of content of methacrylic acid unit To 0.2 g of 2 mm square nitrile rubber, 100 ml of 2-butanone was added and stirred for 16 hours, then 20 ml of ethanol and 10 ml of water were added, and 0.02N aqueous ethanol containing potassium hydroxide with stirring. Using a solution, titration with thymolphthalein as an indicator at room temperature is used to determine the number of moles of carboxyl groups relative to 100 g of nitrile rubber (unit: ephr), and the calculated number of moles of carboxyl groups is converted to the amount of methacrylic acid units. Thus, the content ratio of the methacrylic acid unit in the nitrile rubber was calculated.

Methyl ethyl ketone insoluble polymer latex was poured onto a framed glass plate and allowed to stand for 48 hours at a humidity of 23 ° C. and a relative humidity of 50% to obtain a dry film having a thickness of 1 mm. About 0.2 g of the obtained dried film was precisely weighed, and this was defined as the weight (W1) of the film before immersion. Then, the film before immersion was placed in an 80 mesh cage wire mesh and immersed in 100 mL of methyl ethyl ketone for 24 hours in a state of being placed in the cage wire mesh. And after removing methyl ethyl ketone by drying the film after immersion at 105 degreeC for 1 hour, the weight of the obtained dry film was measured and this was made into the weight (W2) of the dry film after immersion. And from the obtained result, according to the following formula, methyl ethyl ketone insoluble content (MEK insoluble content) was calculated.
Methyl ethyl ketone insoluble content (unit:% by weight) = (weight of dry film after immersion (W2) / weight of dry film before immersion (W1)) × 100

A 1% viscosity thickener of a thickener is dissolved in water to make an aqueous solution having a concentration of 1% by weight, and a viscosity measured at 25 ° C. using a B-type viscometer at a rotation speed of 60 rpm is 1% viscosity. As sought.

Insoluble component particle size of thickener The particle size of the insoluble component was determined by dissolving the thickener in water to a concentration of 1% by weight using a grind gauge (JIS-K5101) to JIS-K5600-5-2. The particle diameter measured by the linear method is shown. Specifically, the aqueous solution is placed on a particle size gauge, and the scraper is pulled toward the front so as to be perpendicular to the gauge, and the scale at the position where three or more lines of 10 mm or more appear continuously is read. The particle size of the insoluble component was determined by the wire method evaluation.
In addition, the particle diameter measured by the said method does not exclude what the insoluble component whose particle diameter exceeds 30 micrometers contains in trace amount in a solution at all. As described in JIS for the accuracy and reproducibility of the measurement method, the absolute value of the difference between two average values obtained by measuring twice is 95% probability and 20% of the gauge range. It is expected to be (targeted). Therefore, in the range of accuracy and reproducibility required by JIS, an insoluble component having a particle diameter exceeding 30 μm may exist in the aqueous solution.

The thickness t ₁ of the osmotic polymer layer and the thickness t _{2 of the} surface polymer layer
For the protective gloves (laminated body), by observing the cross section where the polymer layer of the palm portion of 12 cm from the tip of the middle finger was laminated using an optical microscope (product name “VHX-200”, manufactured by Keyence Corporation), The thickness t ₁ of the osmotic polymer layer and the thickness t ₂ of the surface polymer layer were measured. A specific measurement method will be described with reference to FIG. 1. The thickness t ₁ of the osmotic polymer layer is measured at 10 points from the surface of the fiber base to the deepest part of the infiltrated rubber. The number average value was calculated by calculating. The thickness t ₂ of the surface polymer layer from the surface of the fiber substrate, the distance to the surface of the polymer layer was measured 10 locations were determined by calculating the number average value of the measurement results.

Sensory test gloves (laminated body) are worn by 10 people, and their flexibility is evaluated by the following five grades. The average score is obtained, and the average score is the highest. The closest score was used as the evaluation score in each example (for example, when the average value was 4.1, “4: soft” or the like).
5: Very soft 4: Soft 3: Slightly soft 2: Hard 1: Very hard

Membrane molded body and protective glove Young's modulus Polymer for measurement by cutting the film molded body prepared by removing the volatile content of latex or protective gloves (laminate) into 60mm x 60mm shape A sample was obtained. Then, for the measurement sample, using the indentation test apparatus 20 shown in FIG. 2 (product name “HG1003-SL”, manufactured by Horiuchi Electric Co., Ltd. as the measurement unit), a film molded body is obtained according to the method described above. Alternatively, the Young's modulus of protective gloves was measured. Specific conditions were as shown below. In the measurement, the resin tape is attached to the portions corresponding to the plurality of suction holes of the suction table 30 of the measurement sample, and the spherical indenter is applied from the polymer layer side while performing suction by the suction table 30. The measurement was performed by pushing. In the measurement of the protective gloves, a polymer tape is applied to the surface opposite to the surface (measurement surface) on which the polymer layer of the measurement sample is formed, and suction is performed by the suction table 30 while the polymer is being suctioned. Measurement was performed by pushing a spherical indenter from the layer side. Moreover, the measurement was performed about three places of the measurement sample of 60 mm x 60 mm, the average value of the measurement result of three Young's modulus was calculated | required, and this was made into the Young's modulus of each Example.
Spherical indenter: SUS spherical indenter with a diameter of 10 mm Indentation speed: 0.5 mm / s
Maximum load: 0.5N
Initial position of spherical indenter: -6 mm (height position from suction table 30 to 6 mm)

A sample for measurement was obtained by cutting the palm portion of the bending stiffness protective glove (laminate) into a shape of 60 mm × 60 mm. Then, when the measurement sample was bent using a bending tester (product name “KES-FB2” manufactured by Kato Tech Co., Ltd.) with the test conditions set to SENS20 and bending 2 cm ⁻¹ , the rubber layer was attached to the inner surface. The bending stiffness was measured by bending in the direction. The measurement was performed 5 times, and the average value was defined as the bending rigidity of each example.

The abrasion resistance abrasion test was evaluated using a Martindale abrasion tester (product name “STM633”, manufactured by SATRA) in accordance with the method described in EN388. Specifically, for the protective gloves (laminated body), friction was repeated while applying a predetermined load, and the number of frictions until breakage was obtained. According to the number of frictions until breakage, it is divided into levels from level 0 to level 4, and the higher the level, the better the wear resistance.
LEVEL 4: 8,000 or more revolutions LEVEL 3: 2,000 or more revolutions and less than 8,000 revolutions LEVEL 2: 500 or more revolutions and less than 2,000 revolutions LEVEL 1: 100 or more revolutions and 500 Less than rotation LEVEL 0: Number of rotations less than 100

About the appearance protective gloves (laminated body), the polymer layer was observed visually and the appearance was evaluated according to the following criteria.
A: No cracks or pinholes were confirmed in the polymer layer B: Only cracks were confirmed in the polymer layer C: Only pinholes were confirmed in the polymer layer

Production Example 1 of Polymer Latex (Production of Nitrile Rubber Latex (A-1))
In a reactor, 180 parts of ion-exchanged water, 25 parts of an aqueous sodium dodecylbenzenesulfonate solution having a concentration of 10% by weight, 20 parts of acrylonitrile, 5 parts of methacrylic acid, and 0.6 part of t-dodecyl mercaptan (molecular weight regulator) were added. In order, the internal gas was replaced with nitrogen three times, and then 75 parts of 1,3-butadiene was charged. The reactor was kept at 5 ° C., and 0.1 parts of cumene hydroperoxide (polymerization initiator), a reducing agent, and a chelating agent were charged in appropriate amounts, and the polymerization reaction was continued for about 16 hours with stirring. Subsequently, 0.1 part of a 10 wt% hydroquinone aqueous solution (polymerization terminator) was added to stop the polymerization reaction at a polymerization conversion rate of 85%, and then the residual monomer was removed using a rotary evaporator at a water temperature of 60 ° C. Thereafter, it was concentrated to obtain a nitrile rubber latex (A-1) (solid content concentration of about 30% by weight). In the resulting latex (A-1) of nitrile rubber, the composition of the nitrile rubber and the amount of methyl ethyl ketone insoluble matter were measured, and the Young's modulus of the molded film obtained by removing the volatile matter was measured. The results are shown in Table 2.

Production Example 2 (Production of nitrile rubber latex (A-2))
The amount of acrylonitrile used is 20 to 27 parts, the amount of t-dodecyl mercaptan (molecular weight modifier) is 0.6 to 0.5 parts, and the amount of 1,3-butadiene is 75 to 68 parts. A nitrile rubber latex (A-2) was obtained in the same manner as in Production Example 1, except that the respective changes were made. The results are shown in Table 2.

Production Example 3 (Production of nitrile rubber latex (A-3))
The amount of acrylonitrile used is 20 to 37 parts, the amount of t-dodecyl mercaptan (molecular weight modifier) is 0.6 to 0.3 parts, and the amount of 1,3-butadiene is 75 to 58 parts. A nitrile rubber latex (A-3) was obtained in the same manner as in Production Example 1, except that the respective changes were made. The results are shown in Table 2.

Production Example 4 (Production of nitrile rubber latex (A-4))
The amount of acrylonitrile used is 20 to 15 parts, the amount of t-dodecyl mercaptan (molecular weight modifier) is 0.6 to 0 parts, and the amount of 1,3-butadiene is 75 to 80 parts. A nitrile rubber latex (A-4) was obtained in the same manner as in Production Example 1 except that each was changed, and the measurement was performed in the same manner. The results are shown in Table 2.

Production Example 5 (Production of nitrile rubber latex (A'-5))
The amount of acrylonitrile used is 20 to 42 parts, the amount of t-dodecyl mercaptan (molecular weight modifier) is 0.6 to 0.4 parts, and the amount of 1,3-butadiene is 75 to 53 parts. A nitrile rubber latex (A′-5) was obtained in the same manner as in Production Example 1, except that each was changed. The results are shown in Table 2.

Production Example 6 (Production of nitrile rubber latex (A'-6))
The amount of acrylonitrile used is 20 to 30 parts, the amount of methacrylic acid is 5 to 12 parts, the amount of t-dodecyl mercaptan (molecular weight modifier) is 0.6 to 0.5 parts, 1 A nitrile rubber latex (A′-6) was obtained and measured in the same manner as in Production Example 1 except that the amount of 1,3-butadiene was changed from 75 parts to 58 parts. The results are shown in Table 2.

Example 1
Preparation of latex composition for dip molding As the polymer latex, the latex (A-2) of the nitrile rubber produced in Production Example 2 was prepared, and each 100 parts of the nitrile rubber in the latex of the nitrile rubber was converted into solid content. Thus, water of each compounding agent was prepared so that colloidal sulfur (manufactured by Hosoi Chemical Co., Ltd.) 1.0 part, zinc dibutyldithiocarbamate (manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.) 0.5 part, and zinc oxide 2.0 parts. A dispersion was prepared, and the prepared aqueous dispersion was added to obtain a latex composition. In addition, when adding the aqueous dispersion of each compounding agent, a predetermined amount of the aqueous dispersion of each compounding agent was slowly added while the latex was stirred. Thereafter, the solid content concentration of the latex composition was adjusted, and then aging (also referred to as pre-vulcanization) was performed at a temperature of 30 ° C. for 48 hours. Then, carboxymethylcellulose (B-1) (trade name “WS-C”, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as a thickener for the latex composition after aging (insoluble component particle size: 20 μm, 1% Viscosity: 250 mPa · s, degree of etherification: 0.6 to 0.7) was added at a rate of 0.7% by weight, and a B-type viscometer was used at a temperature of 25 ° C. and a solid content concentration of 45% by weight. A latex composition for dip molding was obtained by adjusting the viscosity measured at a rotation speed of 10 rpm to 2,800 mPa · s.

Preparation of Coagulant Solution A methanol solution prepared by dissolving 2.0% by weight of calcium nitrate as a coagulant in methanol was prepared as a coagulant solution.

Manufacture of laminate (protective gloves) A metal glove mold covered with a glove-shaped fiber substrate (material: nylon, substrate layer average thickness d of fiber substrate: 0.7 mm, 13 gauge) It was immersed in the solution for 5 seconds, pulled up from the coagulant solution, and then dried under conditions of a temperature of 30 ° C. for 60 seconds. Thereafter, the metal glove mold was dipped in the above dip molding latex composition for 3 seconds, pulled up from the dip molding latex composition, and then dried under the conditions of a temperature of 30 ° C. for 30 minutes. Next, the nitrile rubber in the polymer layer was subjected to a crosslinking treatment by performing a heat treatment under conditions of a temperature of 100 ° C. for 60 minutes. Next, protective gloves (laminate) were obtained by peeling the fiber base material on which the polymer layer was formed from the metal glove mold. About the obtained protective gloves (laminated body), according to the method mentioned above, the measurement of the thickness t ₁ of the penetrating polymer layer, the measurement of the thickness t ₂ of the surface polymer layer, the sensory test, the measurement of Young's modulus, the wear resistance, And the appearance was evaluated. The results are shown in Table 1.

Example 2
As a thickener to be added to the latex composition, carboxymethylcellulose (B-2) (trade name “Daicel1150”, manufactured by Daicel Finechem) instead of carboxymethylcellulose (B-1) (insoluble component particle size: 28 μm, 1 % Viscosity: 300 mPa · s, degree of etherification: 0.6 to 0.8) at a ratio of 0.65 wt%, the viscosity of the latex composition for dip molding was adjusted to 3,000 mPa · s. Except for the above, protective gloves (laminated body) were obtained in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

Example 3
As a thickener to be added to the latex composition, carboxymethylcellulose (B-3) (trade name “Daicel1190”, manufactured by Daicel Finechem) instead of carboxymethylcellulose (B-1) (insoluble component particle size: 25 μm, 1 % Viscosity: 1,800 mPa · s, degree of etherification: 0.6 to 0.8) at a ratio of 0.4% by weight, the viscosity of the latex composition for dip molding is 3,200 mPa · s. Except having adjusted, it carried out similarly to Example 1, obtained the protective glove (laminated body), and evaluated similarly. The results are shown in Table 1.

Example 4
After pulling up from the coagulant solution, a protective glove (laminated body) was obtained and evaluated in the same manner as in Example 1 except that it was dried at a temperature of 30 ° C. for 20 seconds. The results are shown in Table 1.

Comparative Example 1
After pulling up from the coagulant solution, a protective glove (laminated body) was obtained and evaluated in the same manner as in Example 1 except that it was dried at a temperature of 30 ° C. for 120 seconds. The results are shown in Table 1.

Comparative Example 2
As a thickener to be added to the latex composition, carboxymethyl cellulose (B′-5) (trade name “Daicel 1120”, manufactured by Daicel Finechem) instead of carboxymethyl cellulose (B-1) (insoluble component particle size: 15 μm, The viscosity of the latex composition for dip molding is adjusted to 2,500 mPa · s by using 1.5% by weight of 1% viscosity: 20 mPa · s, degree of etherification: 0.6 to 0.8). A protective glove (laminate) was obtained in the same manner as in Example 1 except that the evaluation was performed in the same manner. The results are shown in Table 1.

Comparative Example 3
As a thickener added before aging of the latex composition, carboxymethylcellulose (B′-7) (trade name “BSH-6”, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (instead of carboxymethylcellulose (B-1)) Insoluble component particle size: 50 μm, 1% viscosity: 4,000 mPa · s, degree of etherification: 0.65 to 0.75) at a ratio of 0.1% by weight, the latex composition for dip molding A protective glove (laminate) was obtained and evaluated in the same manner as in Example 1 except that the viscosity was adjusted to 3,500 mPa · s. The results are shown in Table 1.

As shown in Evaluation Table 1 of Examples 1 to 4 and Comparative Examples 1 to 3, the ratio of the thickness t ₁ of the osmotic polymer layer to the thickness t ₂ of the surface polymer layer (t ₁ / t ₂ ), and the substrate The laminated body in which the Young's modulus in the portion where the polymer layer was laminated on each was controlled within a predetermined range, both of the sensory test and the appearance evaluation result were good, so it was excellent in flexibility and the appearance Were also good (Examples 1 to 4).

On the other hand, when the Young's modulus of the laminate was too high, the laminate had a poor sensory test evaluation result and was inferior in flexibility (Comparative Examples 1 to 3). In particular, Comparative Example 1, by the thickness t ₁ of the osmopolymer layer of the laminate is thicker, the Young's modulus of the laminate becomes higher, by which the evaluation results of the sensory test is deteriorated, flexibility It was particularly inferior.

Example 5
Preparation of Dip Molding Latex Composition Colloidal sulfur (made by Hosoi Chemical Industry Co., Ltd.) in terms of solid content with respect to 100 parts of nitrile rubber in latex in the nitrile rubber latex (A-1) produced in Production Example 1. ) 1.0 parts, zinc dibutyldithiocarbamate (manufactured by Ouchi Shinsei Chemical Co., Ltd.), and 0.5 parts of zinc oxide, and 2.0 parts of zinc oxide. The liquid was added to obtain a latex composition. In addition, when adding the aqueous dispersion of each compounding agent, a predetermined amount of the aqueous dispersion of each compounding agent was slowly added while the latex was stirred. Thereafter, the solid content concentration of the latex composition was adjusted, and then aging (also referred to as pre-vulcanization) was performed at a temperature of 30 ° C. for 48 hours. Then, a thickener (trade name “Aron A-7100”, manufactured by Toagosei Co., Ltd.) was added to the latex composition after aging at a ratio of 0.4% by weight, and the temperature was 25 ° C. and the solid content concentration was 45. A latex composition for dip molding was obtained by using a B-type viscometer under the condition of wt% and adjusting the viscosity measured at a rotational speed of 10 rpm to 3,000 mPa · s.

Manufacture of laminate (protective gloves) A metal glove mold covered with a glove-shaped fiber substrate (material: nylon, substrate layer average thickness d of fiber substrate: 0.7 mm, 13 gauge) It was immersed in the solution for 5 seconds, pulled up from the coagulant solution, and then dried under conditions of a temperature of 30 ° C. for 60 seconds. Thereafter, the metal glove mold was dipped in the above dip molding latex composition for 3 seconds, pulled up from the dip molding latex composition, and then dried under the conditions of a temperature of 30 ° C. for 30 minutes. Next, the nitrile rubber in the polymer layer was subjected to a crosslinking treatment by performing a heat treatment under conditions of a temperature of 100 ° C. for 60 minutes. Next, protective gloves (laminate) were obtained by peeling the fiber base material on which the polymer layer was formed from the metal glove mold. About the obtained protective gloves (laminated body), according to the method mentioned above, the measurement of the thickness t ₁ of the penetrating polymer layer, the measurement of the thickness t ₂ of the surface polymer layer, the sensory test, the measurement of Young's modulus, and the evaluation of the appearance Went. The results are shown in Table 2.

Example 6
A protective glove (laminate) was obtained in the same manner as in Example 5 except that the nitrile rubber latex (A-2) produced in Production Example 2 was used instead of the nitrile rubber latex (A-1). The same evaluation was performed. The results are shown in Table 2.

Example 7
A protective glove (laminate) was obtained in the same manner as in Example 5 except that the nitrile rubber latex (A-3) produced in Production Example 3 was used instead of the nitrile rubber latex (A-1). The same evaluation was performed. The results are shown in Table 2.

Example 8
A protective glove (laminate) was obtained in the same manner as in Example 5 except that the nitrile rubber latex (A-4) produced in Production Example 5 was used instead of the nitrile rubber latex (A-1). The same evaluation was performed. The results are shown in Table 2.

Comparative Example 4
A protective glove (laminate) was prepared in the same manner as in Example 5 except that the nitrile rubber latex (A′-5) produced in Production Example 5 was used instead of the nitrile rubber latex (A-1). Obtained and evaluated in the same manner. The results are shown in Table 2.

Comparative Example 5
A protective glove (laminate) was prepared in the same manner as in Example 5 except that the nitrile rubber latex (A′-6) produced in Production Example 6 was used instead of the nitrile rubber latex (A-1). Obtained and evaluated in the same manner. The results are shown in Table 2.

Table 2 shows the measurement results of Examples 5 to 8 and Comparative Examples 4 and 5, and Evaluation Examples 5 to 8 and Comparative Examples 4 and 5. FIG. 4 shows a graph in which the measurement results of the Young's modulus of the film molded body and the Young's modulus of the protective gloves are plotted in association with the results of the sensory test. That is, exemplifying Example 5, the sensory test was 5, the Young's modulus of the film molded body was 2,100 kPa, and the Young's modulus of the protective glove was 211 kPa, so the measurement results of the Young's modulus of the film molded body are shown. Sensory test: 5, sensory test: 5, Young's modulus (left axis): plot at a position of 2,100 kPa, and “square plot” showing the measurement result of Young's modulus of protective gloves: Sensory test: 5, Young's modulus (Right axis): Plotted at a position of 211 kPa. The same applies to Examples 6 to 8 and Comparative Examples 4 and 5.

As is clear from the results in Table 2, the ratio of the thickness t ₁ of the osmotic polymer layer to the thickness t ₂ of the surface polymer layer (t ₁ / t ₂ ), and the portion where the polymer layer is laminated on the substrate The laminates in which the Young's moduli of each were controlled within a predetermined range had good sensory tests and excellent flexibility (Examples 5 to 8).
On the other hand, when the Young's modulus of the laminate was too high, the laminate had poor sensory test evaluation results and poor flexibility (Comparative Examples 4 and 5).

As is clear from the results of Table 2 and FIG. 4, the Young's modulus of the film molded body and the Young's modulus of the laminate obtained according to the measurement method described above are in good agreement with the results of the sensory test for protective gloves. As a result. That is, the lower the Young's modulus of the film molded body and the Young's modulus of the laminated body, the better the result of the sensory test. The higher the Young's modulus of the film molded body and the Young's modulus of the laminated body, the worse the result of the sensory test. As a result, there is a certain correlation between them. Therefore, the Young's modulus of the film molded body and the Young's modulus of the laminate obtained according to the measurement method described above are appropriate as an index of the flexibility of the protective gloves. It can be confirmed that it can be used.

Example 9
Preparation of Dip Molding Latex Composition In the same manner as in Example 5, a nitrile rubber latex (A-2) produced in Production Example 2 was prepared as a polymer latex, and 100 parts of nitrile rubber in the nitrile rubber latex was prepared. Respectively, in terms of solid content, 1.0 part of colloidal sulfur (manufactured by Hosoi Chemical Co., Ltd.), 0.5 part of zinc dibutyldithiocarbamate (manufactured by Ouchi Shinsei Chemical Co., Ltd.), and 2.0 parts of zinc oxide. Thus, the aqueous dispersion of each compounding agent was prepared, and the prepared aqueous dispersion was added to obtain a latex composition. In addition, when adding the aqueous dispersion of each compounding agent, a predetermined amount of the aqueous dispersion of each compounding agent was slowly added while the latex was stirred. Thereafter, the solid content concentration of the latex composition was adjusted, and then aging (also referred to as pre-vulcanization) was performed at a temperature of 30 ° C. for 48 hours. Then, Aron A-7100 (manufactured by Toa Gosei Co., Ltd.) is added as a thickener to the latex composition after aging at a ratio of 0.4% by weight, and the temperature is 25 ° C. and the solid content concentration is 45% by weight. A latex composition for dip molding was obtained by using a B-type viscometer and adjusting the viscosity measured at 10 rpm to 3,000 mPa · s.

Manufacture of laminate (protective gloves) A metal glove mold covered with a glove-shaped fiber substrate (material: nylon, substrate layer average thickness d of fiber substrate: 0.7 mm, 13 gauge) It was immersed in the solution for 5 seconds, pulled up from the coagulant solution, and then dried at a temperature of 30 ° C. for 1 minute. Thereafter, the metal glove mold was dipped in the above dip molding latex composition for 3 seconds, pulled up from the dip molding latex composition, and then dried under the conditions of a temperature of 30 ° C. for 30 minutes. Next, the nitrile rubber in the rubber layer was subjected to a crosslinking treatment by performing a heat treatment under conditions of a temperature of 100 ° C. for 60 minutes. Next, protective gloves (laminate) were obtained by peeling the fiber base material on which the rubber layer was formed from the metal glove mold. About the obtained protective gloves (laminated body), according to the method mentioned above, the measurement of the thickness t ₁ of the osmotic rubber layer, the measurement of the thickness t ₂ of the surface rubber layer, the sensory test, the measurement of Young's modulus, the bending rigidity, and the wear resistance The sex was measured. The results are shown in Table 3.

Example 10
As a thickener added to the latex composition after aging, Aron A-7100 (manufactured by Toa Gosei Co., Ltd.) is used in a proportion of 0.3% by weight, so that the viscosity of the dip molding latex composition is 2,000 mPas. -Except having adjusted to s, it carried out similarly to Example 9, obtained the protective glove (laminated body), and evaluated similarly. The results are shown in Table 3.

Example 11
A protective glove (laminate) was obtained in the same manner as in Example 9 except that the drying condition after lifting the metal glove mold from the coagulant solution was 30 ° C. for 30 seconds. Went. The results are shown in Table 3.

Example 12
As a thickener added to the latex composition after aging, Aron A-7100 (manufactured by Toa Gosei Co., Ltd.) is used at a ratio of 0.6% by weight, so that the viscosity of the dip-molding latex composition is 5,000 mPas. -Adjusting to s and obtaining a protective glove (laminate) in the same manner as in Example 9 except that the time for immersing the metal glove mold in the dip-forming latex composition was changed to 5 seconds, Evaluation was performed in the same manner. The results are shown in Table 3.

Comparative Example 6
A protective glove (laminate) was obtained and evaluated in the same manner as in Example 9 except that the drying conditions after the metal glove mold was pulled up from the coagulant solution were set to a temperature of 30 ° C. and 90 seconds. Went. The results are shown in Table 3.

Comparative Example 7
After pulling up the metal glove mold from the coagulant solution, drying it at a temperature of 30 ° C. for 60 seconds, and then immersing the metal glove mold in the latex composition for dip molding, that is, the metal glove mold Was dipped in a latex composition for dip molding for 3 seconds, pulled up, and then subjected to protective gloves (as in Example 9) except that the operation of drying at a temperature of 30 ° C. for 30 minutes was repeated twice. A laminate was obtained and evaluated in the same manner. The results are shown in Table 3.

Evaluation results of Examples 9 to 12 and Comparative Examples 6 and 7 Table 3 shows the measurement results of Examples 9 to 12 and Comparative Examples 6 and 7. Further, FIG. 5 shows the Young's modulus and the results of the bending test plotted in correspondence with the results of the sensory test. That is, exemplifying Example 9, the sensory test was 4, the Young's modulus was 359 kPa, and the bending stiffness was 0.340 gf · cm ² / cm. Therefore, the “square plot” indicating the measurement result of the Young's modulus was The test was plotted at a position of 4, Young's modulus: 359 kPa, and a “round plot” showing the measurement result of the bending stiffness was plotted at a position of sensory test: 4, bending stiffness: 0.340 gf · cm ² / cm. The same applies to Examples 10 to 12 and Comparative Examples 6 and 7.

As is apparent from the results in Table 3, the ratio of the thickness t ₁ of the osmotic polymer layer to the thickness t ₂ of the surface polymer layer (t ₁ / t ₂ ), and the portion where the polymer layer is laminated on the substrate The laminates in which the Young's moduli of each were controlled within a predetermined range had good sensory tests and excellent flexibility (Examples 9 to 12).
On the other hand, when the ratio (t ₁ / t ₂ ) of the thickness t ₁ of the osmotic polymer layer to the thickness t ₂ of the surface polymer layer is outside the scope of the present invention, and the Young's modulus of the laminate is too high. The laminate had a poor sensory test evaluation result and was inferior in flexibility (Comparative Examples 6 and 7).

As is apparent from the results of Table 3 and FIG. 5, the Young's modulus obtained according to the measurement method of the present invention was in good agreement with the results of the sensory test. That is, the worse the sensory test result, the higher the Young's modulus, and the better the sensory test result, the lower the Young's modulus, and there is a certain correlation between them. It can be confirmed that the Young's modulus obtained according to the measuring method can be appropriately used as an index of flexibility.
On the other hand, the result of the bending stiffness was inconsistent with the result of the sensory test and was not appropriate as an index of flexibility.

Claims

A laminate comprising a substrate and a polymer layer formed from a polymer latex,
The polymer layer partially covers the base material in a state of permeating the base material,
Wherein one of the polymer layers, which is a penetration portion to the substrate osmopolymers layer, the thickness from the surface of the substrate and t 1, the surface polymer layer is a portion that covers the substrate, When the thickness from the surface of the base material is t 2 , the ratio of the thickness t 1 of the osmotic polymer layer to the thickness t 2 of the surface polymer layer (t 1 / t 2 ) is 0.15 to 5.0,
The laminated body whose Young's modulus in the part by which the said polymer layer was laminated | stacked on the said base material is 800 kPa or less.
The laminate according to claim 1, wherein the thickness t 1 of the osmotic polymer layer is 0.05 to 0.6 mm.
3. The laminate according to claim 1, wherein the polymer latex for forming the polymer layer has a Young's modulus of 10,000 kPa or less when the volatile component is removed to form a film molded body. body.
The laminate according to claim 3, wherein the polymer latex for forming the polymer layer contains, as a polymer, a conjugated diene rubber having a conjugated diene monomer unit content of 52 to 78 wt%. .
The polymer latex for forming the polymer layer contains, as a polymer, a conjugated diene rubber having a content of α, β-ethylenically unsaturated nitrile monomer units of 20 to 40% by weight. Item 5. A laminate according to item 3 or 4.
The polymer latex for forming the polymer layer contains, as a polymer, a conjugated diene rubber having a carboxyl group-containing ethylenically unsaturated monomer unit content of 2 to 10% by weight. 6. The laminate according to any one of 5 to 5.
A method of measuring the flexibility of a rubber film molded body or a laminate having a rubber layer,
Rubber film molding for measuring flexibility based on indentation load and displacement due to indentation when the indenter is pushed into the film molding or the laminate with a predetermined indentation load. Method for measuring flexibility of laminate having body or rubber layer.
The flexibility measurement method according to claim 7, wherein the flexibility is measured based on an indentation load and a displacement due to the indentation when the indenter is indented with a plurality of different indentation loads.
The method of measuring flexibility according to claim 7 or 8, wherein the Young's modulus of the film molded body or the laminate is obtained based on an indentation load when the indenter is indented and a displacement due to the indentation.
The method for measuring flexibility according to any one of claims 7 to 9, wherein the film molded body or the laminate is used in contact with a human body.