JP2001040316A - Latex for carpet resin adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide carpets having excellent moldability, thermoforming properties, heat-resistant shape retention, and rigidity, and a latex for carpet resin adhesives which is used in the production of these carpets. SOLUTION: A latex for carpet resin adhesives is a latex of a copolymer composed of 5-30 wt.% acid group-containing ethylenically unsaturated monomer units and 70-95 wt.% olefinic monomer units copolymerizable therewith and having a glass transition temperature of 100-150 deg.C. Carpets contain this latex for carpet resin adhesives.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carpet and a latex for a resin adhesive for a carpet, and more particularly to a carpet excellent in moldability, thermoformability, heat-shaping property and rigidity, and a carpet for obtaining the carpet The present invention relates to a latex for a resin adhesive.

[0002]

2. Description of the Related Art Conventionally, carpets for automobile interiors are coated with an adhesive containing butadiene-styrene copolymer latex or the like as a main component and impregnated, and then thermoformed and heat-resistant (80 to 95%). It is manufactured by a two-stage processing method of laminating a thermoplastic resin sheet for the purpose of imparting its shape in a high-temperature atmosphere of about ° C. The carpet thus obtained is cut,
After being formed into a desired shape by press molding by heating, it is used by being incorporated into an automobile. However, this two-stage processing method complicates the carpet manufacturing process,
For the purpose of improving productivity and reducing costs, there has been proposed a one-step processing method for imparting thermoformability to an adhesive without laminating a thermoplastic resin (Japanese Patent Laid-Open No. 53-52).
776). As an adhesive used in this one-step processing method, a resin emulsion having a glass transition temperature of 80 to 110 ° C., a synthetic rubber latex having a glass transition temperature of −50 to 0 ° C., and a crosslinking agent having reactivity with a carboxyl group are used. Adhesive (JP-A-63-178182), a copolymer having a glass transition temperature of 80 to 140 ° C and a copolymer having a glass transition temperature of -90 to 50 ° C in the same particle. / Adhesive containing in the form of particles such as shell structure (JP-A-63-196779),
The content of the copolymerized vinyl cyanide compound is 5 to 5.
An adhesive comprising 50% by weight of a latex of a copolymer having a glass transition temperature of 80 ° C. or higher and a latex of a copolymer having a glass transition temperature of 5 to 50 ° C. (JP-A-2-112)
No. 485) has been proposed, but there is a problem that the production becomes complicated because it is necessary to mix latex or change the polymerization step from the middle. In addition, in this one-step processing method, the steps in the production of carpet are simplified, and the moldability and thermoformability are sufficient, but a carpet satisfying the heat-resistant shape retention property has not been obtained. As described above, these carpets for automobile interiors are molded and used, but if the heat-resistant shape retention property is not sufficient, the carpet molded into a desired shape will be deformed at the time of assembling, so that the carpet manufacturing site Therefore, it is not possible to integrally manufacture a molded product, and it is necessary to perform thermoforming again when installing the product in an automobile. Therefore, there is a problem that the process becomes complicated.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention solves the above-mentioned conventional problems and makes it possible to produce a carpet having excellent moldability, thermoformability, heat-resistant shape retention and rigidity, and to manufacture the carpet. It is an object of the present invention to provide a latex for a resin adhesive for a carpet.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that a copolymer having a specific composition and a glass transition temperature of 100 to 150 ° C. It has been found that the above-mentioned problems can be achieved by using latex, and the present invention has been completed based on this finding.

Thus, according to the present invention, there is provided a copolymer comprising 5 to 30% by weight of an acid group-containing ethylenically unsaturated monomer unit and 70 to 95% by weight of an olefin monomer unit copolymerizable therewith. A latex for a resin adhesive for carpet, wherein the latex has a glass transition temperature of 100 to 150 ° C.

Further, according to the present invention, there is provided a carpet comprising the latex for a resin adhesive for a carpet.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The copolymer constituting the latex for a resin adhesive for a carpet of the present invention comprises 5 to 30% by weight of an acid group-containing ethylenically unsaturated monomer unit and 70 to 95 of an olefin monomer unit copolymerizable therewith. % By weight.

The ethylenically unsaturated monomer containing an acid group used for the synthesis of the copolymer is, for example, an ethylenically unsaturated monomer having an acid group such as a carboxyl group, a sulfonic acid group, a phosphoric acid group and the like. There is no particular limitation. Specific examples of these acid group-containing ethylenically unsaturated monomers include, for example, ethylenically unsaturated carboxylic acid monomers, ethylenically unsaturated sulfonic acid monomers, ethylenically unsaturated phosphoric acid monomers, and the like. Is mentioned.

The carboxyl group-containing ethylenically unsaturated monomers include, for example, α, β-ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; fumaric acid, maleic acid, itaconic acid, butene Α, β-ethylenically unsaturated polycarboxylic acids such as tricarboxylic acids; and partially esterified products of α, β-ethylenically unsaturated polycarboxylic acids such as monoethyl maleate and monomethyl itaconate.

The sulfonic acid group-containing ethylenically unsaturated monomers include, for example, α, β-ethylenically unsaturated sulfonic acids such as vinyl sulfonic acid, styrene sulfonic acid and (meth) allyl sulfonic acid; 2-acrylamide- 2-methylpropanesulfonic acid, 2-acrylamide-2-hydroxypropanesulfonic acid, 3-sulfopropane (meth)
Acrylic acid esters, bis- (3-sulfopropyl) itaconic acid esters and the like can be mentioned.

Examples of the phosphate group-containing ethylenically unsaturated monomer include vinyl phosphonic acid, vinyl phosphate, bis (methacryloxyethyl) phosphate, diphenyl-2-methacryloyloxyethyl phosphate, and the like.
Examples thereof include dibutyl-2-methacryloyloxyethyl phosphate, dioctyl-2-methacryloyloxyethyl phosphate, and 3-allyloxy-2-hydroxypropane phosphoric acid.

These acid group-containing ethylenically unsaturated monomers can be used as alkali metal salts or ammonium salts. These acid group-containing ethylenically unsaturated monomers can be used alone or in combination of two or more.

Of these acid group-containing ethylenically unsaturated monomers, carboxylic acid group-containing ethylenically unsaturated monomers are preferred, and α, β-ethylenically unsaturated monocarboxylic acids are more preferred. Among the α, β-ethylenically unsaturated monocarboxylic acids, acrylic acid and methacrylic acid are preferred.

The amount of the acid group-containing ethylenically unsaturated monomer unit in the copolymer is 5 to 30% by weight, preferably 7 to 20% by weight, more preferably 7 to 20% by weight of the total monomer units of the copolymer. 8 ~
15% by weight. If the amount is less than 5% by weight, the heat-retaining property is insufficient, and if it exceeds 30% by weight, the moldability of the carpet is poor and powder fall occurs.

Other olefin monomers used for the synthesis of the copolymer have a glass transition temperature of the copolymer of 100 to 1
There is no particular limitation as long as the monomer becomes 50 ° C., for example,
Examples include an aromatic vinyl monomer, an α, β-ethylenically unsaturated carboxylic acid derivative-based monomer, an α, β-ethylenically unsaturated nitrile monomer, and a crosslinkable monomer. Among these olefin monomers, aromatic vinyl monomers,
α, β-ethylenically unsaturated nitrile monomers are preferred.

The aromatic vinyl monomer is not particularly restricted but includes, for example, styrene, methylstyrene, vinyltoluene, chlorostyrene, hydroxymethylstyrene and the like. These can be used alone or in combination of two or more. Of these aromatic vinyl monomers, styrene is preferred.

Examples of the α, β-ethylenically unsaturated acid derivative monomer include α, β-ethylenically unsaturated carboxylic acid ester monomers and α, β-ethylenically unsaturated carboxylic acid amide monomers. Body and the like.

The α, β-ethylenically unsaturated carboxylic acid ester monomer is a substituent such as halogen of α, β-ethylenically unsaturated monocarboxylic acid or α, β-ethylenically unsaturated polycarboxylic acid. Is an ester with various alcohols which may have α, β-ethylenically unsaturated monocarboxylic acid ester monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, (meth) 2-ethylhexyl acrylate, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, methoxymethyl (meth) acrylate, (meth) acrylate
(Meth) acrylates such as ethoxyethyl acrylate, cyanomethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, hydroxyethyl (meth) acrylate, and glycidyl (meth) acrylate; dibutyl maleate and fumaric acid Α, β-ethylenically unsaturated polycarboxylic acid esters such as dibutyl and diethyl maleate;
And the like.

Examples of the α, β-ethylenically unsaturated carboxylic acid amide monomer include (meth) acrylamide,
(Meth) acrylamide monomers such as N-methylol (meth) acrylamide, N, N-dimethylol (meth) acrylamide, and N-methoxymethyl (meth) acrylamide.

Examples of the α, β-ethylenically unsaturated nitrile monomer include (meth) acrylonitrile, fumaronitrile, α-chloroacrylonitrile, α-cyanoethylacrylonitrile and the like. These α, β
-Of the ethylenically unsaturated nitrile monomers, acrylonitrile is preferred.

Examples of the crosslinkable monomer include conjugated divinyl compounds such as divinylbenzene; polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol (meth) A) acrylate and other poly (meth) acrylate compounds.

These copolymerizable olefin monomers may be used alone or in combination of two or more.

The amount of the other olefinic monomer units in the copolymer is 70 to 95% by weight of the total monomers, and the glass transition temperature of the copolymer is controlled to 100 to 150 ° C. Good.

The glass transition temperature of the copolymer is 100 to 15
0 ° C., preferably 105-140 ° C. When the glass transition temperature is lower than 100 ° C., the heat retaining property of the carpet is insufficient, and when the glass transition temperature is higher than 150 ° C., the film-forming property deteriorates and powder falling occurs.

The acid group-containing ethylenically unsaturated monomer unit 5 constituting the latex for the resin adhesive for carpet of the present invention 5
A copolymer consisting of -30% by weight and 70-95% by weight of an olefin monomer unit copolymerizable therewith is 5-30% by weight of an acid group-containing ethylenically unsaturated monomer and copolymerizable therewith. Obtained by copolymerizing 70 to 95% by weight of a suitable olefin monomer. In this case, the polymerization conversion is 90% or more, preferably 95% or more, and more preferably 99% or more.

The latex for carpet resin adhesive of the present invention is usually produced by an emulsion polymerization method. Emulsion polymerization is
Emulsifiers, polymerization initiators, molecular weight regulators, chelating agents and the like are used in an aqueous medium by a known method, and the polymerization temperature at that time is not limited, but is usually 5 to 90 ° C.

The emulsifier used for producing the latex for the resin adhesive for carpet of the present invention is not particularly limited. For example, anionic emulsifiers such as alkyl benzene sulfonate, aliphatic sulfonate and sulfate of higher alcohol; nonionic emulsifiers such as polyethylene glycol alkyl ether type, polyethylene glycol alkyl ester type and polyethylene glycol alkyl phenyl ether type; anion Examples of the moieties include carboxylate, sulfate, sulfonate, phosphate, and phosphate, and the like, and amphoteric surfactants having an amine salt or a quaternary ammonium salt as the cation. it can.

The amount of the emulsifier used is usually 0.1 to 3% by weight, based on the total amount of all the monomers used for the synthesis of the copolymer.
Preferably it is 0.2 to 2% by weight.

The polymerization initiator used for producing the latex for the resin adhesive for carpet of the present invention is not particularly limited.
For example, inorganic peroxides such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, and hydrogen peroxide; t-butyl peroxide, cumene hydroperoxide, p-menthane hydroperoxide,
Di-t-butyl peroxide, t-butyl cumyl peroxide, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t-butyl peroxide Organic peroxides such as isobutyrate; and azo compounds such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyrate, and the like. These polymerization initiators can be used alone or in combination of two or more. Further, the peroxide initiator can be used as a redox polymerization initiator in combination with a reducing agent such as sodium bisulfite.

The amount of the polymerization initiator used is usually from 0.1 to 5% by weight, preferably from 0.5 to 3% by weight, based on the total amount of all the monomers used for the synthesis of the copolymer. is there. As the polymerization initiator, any of batch addition, continuous addition, and division addition can be adopted.

Examples of the molecular weight modifier include α-methylstyrene dimer; t-dodecyl mercaptan, n-
Mercaptans such as dodecyl mercaptan and octyl mercaptan; halogenated hydrocarbons such as carbon tetrachloride, methylene chloride and methylene bromide; sulfur-containing compounds such as tetraethylthiuram disulfide, dipentamethylenethiuram disulfide, diisopropylxanthogen disulfide and the like No. These can be used alone or in combination of two or more.

The amount of the molecular weight modifier to be used is usually 0.05 to 10% based on the total amount of all monomers used for the synthesis of the copolymer.
It is 1.5% by weight, preferably 0.1-1% by weight, more preferably 0.2-0.8% by weight.

In producing the copolymer, a seed polymerization method can be employed. The copolymer composition of the seed latex is not particularly limited, and may be the same or different from the composition of the copolymer. The particle size and the amount of the seed latex to be used may be appropriately selected according to the purpose.

Examples of the method of adding the monomer in the synthesis of the copolymer include a method of adding the whole amount of the monomer at once, a method of adding the monomer continuously or intermittently, and a method of adding the monomer. Is added all at once and reacted to a specific polymerization conversion, and then the remaining monomer is added continuously or intermittently. Either method may be employed. In addition, when each monomer is added continuously or intermittently, the composition of each monomer may be consistently the same or may be changed sequentially.

The latex for resin adhesive for carpet of the present invention may contain a pH adjuster, a deodorant, a preservative, a fragrance, a dispersant, etc. which are usually added to the latex. These additives may be added at any time after the polymerization of the copolymer latex.

As the pH adjuster, a base is usually used. Specifically, the base used is a hydroxide of an alkali metal such as sodium hydroxide or potassium hydroxide;
Hydroxides of alkaline earth metals such as calcium hydroxide and magnesium hydroxide; ammonia; amines such as triethylamine and triethanolamine; and the like are used.
You.

The latex of the copolymer preferably has a pH of 7.0 to 11.0, more preferably 8.0 to 11.0.
0.0. If the pH is less than 7.0, the dissociation of the acid groups is small, and the fusion between latex particles is difficult to occur, resulting in poor film-forming properties. It becomes difficult.

[0037]

The present invention will be described in more detail with reference to the following examples. The parts and percentages in the examples are on a weight basis unless otherwise specified, and the weight of the copolymer latex is in terms of solid content.

[Method of evaluating physical properties] (Preparation of molded carpet) Tabletop foaming machine (HM-300:
A copolymer latex foamed to a desired expansion ratio by Toshiba) is flowed on a glass plate partitioned to have a constant thickness, and the back surface of a cotton needle punch carpet having a cotton grain of 450 g / m ² is applied. After placing in contact and applying pressure with an iron roll to transfer and impregnate the latex to a dry weight of 100 g / m ² , it is dried in an oven at 170 ° C. for 5 minutes to produce a molded carpet. did.

(Moldability) The adhesion of the binder to the carpet molded at 170 ° C. was evaluated according to the following criteria. ○: No powder dropping △: Some powder dropping ×: Many powder droppings

(Discoloration during thermoforming) The molded carpet is cut into a size of 5 cm × 10 cm, and is cut in an oven.
The carpet was heated at 30 ° C. for 3 minutes and then pressed at room temperature into a mold having an angle of 90 °, and the discoloration of the carpet was evaluated according to the following criteria. ：: no discoloration Δ: slight discoloration

(Heat-Resistant Shape Retaining Property) The thermoformed carpet molded at 90 ° was heat-treated in a hot-air dryer at 100 ° C. for 3 hours, and the state of angle retention was evaluated according to the following criteria. ：: Angle 70 ° or more △: Angle 60 to 70 ° ×: Angle 60 ° or less

(Rigidity) The thermoformed carpet molded at 90 ° was cut into a size of 2 cm × 7 cm, and evaluated using a Gurley type flexibility tester by numerical values when the sample was deformed. The higher the value, the higher the stiffness.

Example 1 In a vessel equipped with a stirrer purged with nitrogen, 72 parts of styrene, 18 parts of acrylonitrile, 10 parts of methacrylic acid, 0.6 part of soft dodecylbenzenesulfonic acid, 55 parts of ion-exchanged water and adjustment of the degree of polymerization 0.3 parts of n-dodecyl mercaptan was charged as an agent and emulsified to prepare a monomer emulsion. 10% of the monomer emulsion was transferred to a polymerization vessel equipped with a stirrer, 45 parts of ion-exchanged water was added, the atmosphere was replaced with nitrogen, the temperature was raised to 80 ° C, and 0.6 part of potassium persulfate was added. Polymerized for hours. The remaining emulsion was continuously dropped into the polymerization vessel over 4 hours, and after completion of the dropping, the temperature was raised to 85 ° C. and the mixture was aged for 4 hours, and the polymerization was terminated by adding a reaction terminator. At this time, the polymerization conversion was 99%. PH of copolymer latex
And the concentration was adjusted so that the solid content concentration was 50% and the pH was 8.
5 was obtained. Table 1 shows the properties of the obtained latex.

[0044]

[Table 1]

(Examples 2 to 5, Comparative Examples 1 to 3) Solid content concentration was the same as in Example 1 except that the monomer composition and the adjusted latex pH were changed as shown in Table 1. Is 50%
Was obtained. Table 1 shows the properties of the obtained latex.

Example 6 The copolymer latex obtained in Example 1 was foamed to a desired expansion ratio with a tabletop foaming machine (HM-300: manufactured by Toshiba), and then divided so as to have a constant thickness. On the glass plate, 450g / m
^2. Place the polyester needle punch carpet so that the back side is in contact with it, apply pressure with an iron roll to transfer and impregnate the latex so that the dry weight becomes 100 g / m ² , and then place it in an oven at 170 ° C. Let dry for 5 minutes,
A molded carpet was made. Table 1 shows the physical property evaluation results of the obtained molded carpet.

(Examples 7 to 10, Comparative Examples 4 to 6) The same evaluation as in Example 6 was performed using the copolymer latexes obtained in Examples 2 to 5 and Comparative Examples 1 to 3. Table 1 shows the results.

From the evaluation results of the molded carpet shown in Table 1, the following can be understood for the carpet of the comparative example. The carpet of Comparative Example 4 obtained using the latex of Comparative Example 1 in which the acid group-containing unsaturated monomer of the copolymer is less than the range specified in the present invention has a constant moldability and discoloration during thermoforming. Despite being at a level, heat-resistant shape retention and rigidity are poor. The carpet of Comparative Example 5 obtained by using the latex of Comparative Example 2 in which the acid group-containing unsaturated monomer of the copolymer is more than the range specified in the present invention, the discoloration during thermoforming is small, Poor performance, heat-resistant shape retention and rigidity. The carpet of Comparative Example 6 obtained by using the latex of Comparative Example 3 in which the glass transition temperature of the copolymer is higher than the range specified in the present invention has a small discoloration during thermoforming, but has good moldability and heat-resistant shape retention. Poor performance and rigidity.

On the other hand, it can be seen that the carpets of Examples 6 to 10 using the copolymer latex of the present invention are excellent in moldability, thermoformability, heat retention and rigidity.
At this time, it is preferable that the latex has a high pH.

As described above, according to the present invention, it is possible to obtain a carpet excellent in moldability, thermoformability, heat-retaining property and rigidity, and a latex for a resin adhesive for a carpet, which enables the production of the carpet.

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Claims (2)

[Claims] (1) an acid group-containing ethylenically unsaturated monomer unit (5):
A latex of a copolymer comprising 30% by weight and 70 to 95% by weight of an olefin monomer unit copolymerizable therewith, wherein the glass transition temperature of the copolymer is 100 to 15%.
Latex for carpet resin adhesive at 0 ° C. 2. A carpet containing the latex for a resin adhesive for a carpet according to claim 1.