JP3516351B2 - Laminated molding - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated molded product having a pressure-sensitive adhesive layer, and more particularly to a laminated molded product such as a pressure-sensitive adhesive sheet and a label, which can be easily disposed of after use and does not adversely affect the environment. is there.

[0002]

2. Description of the Related Art Conventionally, labels for various containers such as foods and pharmaceuticals, tapes for packaging various transportation containers, and the like have adhesive strength (tack), adhesive strength, cohesive strength, etc. on the back surface of paper or resin. A laminate of acrylic adhesives having physical properties is often used.

[0003]

However, recently, the collection and reuse of the container and the resin-made transport container have been actively carried out, so that the label and tape after use can be easily peeled off. In addition, it is desired that the peeled label or tape itself can be easily discarded, and that the adverse effect on the environment is small. In other words, it is easy to dispose of after use, and even if it is dumped / accumulated as industrial waste, it will be destroyed or decomposed by light and microorganisms,
It has been desired to develop a laminated molded product such as a pressure-sensitive adhesive sheet and a label, which has little adverse effect on the environment.

[0004]

[Means for Solving the Problems] Therefore, the inventors of the present invention have conducted extensive studies to solve such problems, and as a result, a layer composed of the photodegradable and / or biodegradable resin composition (A) was obtained. (Meth) acrylate ( B1 ) 3 with ether bond
0-98% by weight, α, β-unsaturated carboxylic acid or salt thereof
( B2 ) 2 to 20% by weight and copolymerizable with the above monomers
Glass transition temperature consisting of 0 to 68% by weight of monomer ( B3 )
(Tg) A laminated molded product obtained by laminating a layer comprising a pressure-sensitive adhesive composition (B) containing a copolymer having a temperature of -20 ° C or lower is easy to peel off, and the peeled laminated body itself is also easy to discard. In addition, they have found that they have few adverse effects on the environment, and have completed the present invention. The degradability as used in the present invention also means disintegration.
The present invention is described in detail below.

The photodegradable and / or biodegradable resin composition (A) used in the present invention means a photodegradable resin which is decomposed by sunlight, particularly ultraviolet energy, or by the action of microorganisms such as bacteria and bacteria. There is no particular limitation as long as it is a composition composed of a biodegradable resin that is decomposed or a mixture thereof. Examples of the photodegradable resin composition include ethylene-carbon monoxide copolymers, ethylene-vinyl ketone-based copolymers, polybutadiene and isoprene-based rubber. It is obtained by polymerizing with carbon oxide at high temperature under ultrahigh pressure, and the copolymerization ratio of carbon monoxide is often about 0.3 to 10% by weight. Examples of the ethylene-vinyl ketone copolymer include an ethylene-methylene vinyl ketone copolymer and an ethylene-methyl propyl ketone copolymer, and the vinyl ketone copolymerization ratio is often about 0.1 to 10 mol%. However, the copolymerization ratio can be further increased.

As polybutadiene, thermoplastics 1,2
-Polybutadiene, high cis-butadiene rubber, low cis-
Butadiene rubber and the like can be mentioned, and thermoplastic 1,2-polybutadiene in which 90% or more of butadiene is 1,2-bonded is particularly preferable. As the isoprene-based rubber, natural rubber, natural trans-polyisoprene, modified natural rubber, isoprene rubber, trans-polyisoprene, etc. are used, and natural rubber is particularly important. Examples of biodegradable resin compositions include polyvinyl alcohol resins, polyether resins such as polyethylene glycol and polypropylene glycol, aliphatic polyester resins such as polycaprolactone, polyamide resins, and the like.
A mixture of these thermoplastic resins and a starch-based polymer is preferably used, for example, a polyvinyl alcohol-based resin obtained by copolymerizing ethylene, that is, a saponified ethylene-vinyl acetate copolymer and / or polycaprolactone and starch. Examples of the resin composition include a polymer.

When the starch-based polymer is used in combination, the mixing ratio is preferably 20 to 80% by weight, particularly 30 to 70% by weight. When the ratio of the starch-based polymer is too low, biodegradability or When the disintegration property is impaired, while the ratio is too high, the mechanical properties of the molded product become insufficient. However, depending on the application, there may be some deviation from the above mixing ratio.

In the present invention, the above-mentioned mixed system is very useful, but it is preferable to add a polyhydric alcohol as a plasticizer in order to further improve the moldability of the mixture. Has 2 to 4 hydroxyl groups in the molecule and has a melting point of 40 ° C. or higher, preferably 40 to
150 ° C, molecular weight 600 or less, preferably 100 to 30
0 is used, and specifically, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, neopentyl glycol, hydrobenzoin, 1,2-cyclohexane. Examples thereof include diols, dihydric alcohols such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol, trihydric alcohols such as trimethylolpropane and trimethylolethane, and tetrahydric alcohols such as pentaerythritol. 6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol,
Trimethylolpropane and the like are practical.

In addition, if necessary, resin components other than the above (ethylene copolymers and other polyolefins, hydrogenated styrene-butadiene rubber, polyurethane, polyamide, polyhydroxybutyrate, etc.), natural polymers other than starch-based polymers (Polysaccharide-based polymer, cellulose-based polymer, protein-based polymer, etc.), heat stabilizer, extender, filler, lubricant, colorant, flame retardant, water resistance agent, autoxidizer, UV stabilizer, crosslinking Agents, antibacterial agents, herbicides, antioxidants, etc., and urea, alkaline earths, alkali metal hydroxides and mixtures thereof can be added as starch modifying agents.

Further, in the present invention, the above-mentioned photodegradable resin composition and biodegradable resin composition may be mixed and used, and the mixing ratio in that case is the biodegradable resin composition 10.
3 to 70 parts by weight of the photodegradable resin composition with respect to 0 parts by weight,
Particularly, 5 to 40 parts by weight is preferable. Such photodegradability and /
Alternatively, regarding the molding of the biodegradable resin composition (A), it can be molded into a sheet shape of about 10 to 100 μ using an extruder, and the sheet-shaped material is photodegradable or biodegradable according to the present invention. The layer can be made of the resin composition (A).

On the other hand, it is laminated on the layer consisting of the above (A).
That the adhesive composition used in the layer (B) has an error ether bond (meth) acrylate (B1) 30 to 98 wt%, alpha, beta-unsaturated carboxylic acid or its salt (B2) 2 to 2
0% by weight and monomers copolymerizable with the above monomers (B
3) Glass transition temperature (Tg) consisting of 0 to 68% by weight-
20 ° C. Ru following copolymer der. When it is particularly desired to improve the adhesiveness with the polyolefin resin, the acid value is 100 to 300 mg with respect to 95 to 60 parts by weight of the copolymer.
A pressure-sensitive adhesive composition containing 5 to 40 parts by weight of a KOH / g tackifier (B4) is preferable. Hereinafter, the composition (B) will be described in detail.

The (meth) acrylate (B1) having an ether bond used in the present invention is a compound in which an ether bond is introduced into (meth) acrylate by alkoxy or the like, and is 2-ethoxyethyl acrylate or 2-methoxyethyl acrylate. , 3-methoxybutyl acrylate,
Examples thereof include ethyl carbitol acrylate and 2-butoxyethyl acrylate, and 2-ethoxyethyl acrylate and 2-methoxyethyl acrylate are particularly preferably used. Further, the α, β-unsaturated carboxylic acid or a salt thereof (B2) includes acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid and the like, and salts thereof, particularly acrylic acid, methacrylic acid. An acid or the like is preferably used.

Further, other copolymerizable monomers (B
3) includes methyl acrylate, alkyl methacrylic acid alkyl ester having 1 to 3 carbon atoms, vinyl acetate,
There are acrylonitrile, methacrylonitrile, styrene, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, acrylamide, methacrylamide, methylol acrylamide, glycidyl methacrylate, etc. Among them, butyl acrylate, 2- Ethylhexyl acrylate, methyl acrylate, vinyl acetate are preferably used.

In the above-mentioned components (B1) to (B3), it is necessary to select at least one kind from each component (the component (B3) is as necessary), and select two or more kinds from the same components. It is also possible. The blending amount of (B1) and (B2) is 30 to 98% by weight of (B1) and 2 to 20% by weight of (B2), and (B3) is 68% by weight or less as necessary. It can be blended. When the content of (B1) is more than the above range, the adhesive strength is low and the water resistance is poor, and when it is less, the water solubility or alkali solubility is poor. On the other hand, if the content of (B2) is more than the above range, the water resistance will be poor, and at the same time, tackiness will be poor and the adhesive force to the polyolefin resin will be decreased. Further, if the content of (B3) exceeds the above range, the blending amount of (B1) or (B2) decreases, which is not preferable.

The glass transition temperature (Tg) of the acrylic copolymer obtained by such a method is preferably -20 ° C or lower, and when Tg exceeds -20 ° C, the adhesive strength tends to decrease. Further, in the present invention, in order to further improve the adhesiveness with the polyolefin resin, the acid value of the copolymer is 100 to 300 mgKOH / g, preferably 1
It is also useful to blend a tackifier (B4) having a high acid value of 50 to 300 mgKOH / g, and the blending amount thereof is the copolymer / the tackifier (B4) = 95/5 to 60/40.
(Weight ratio), preferably 90/10 to 70/30 (weight ratio). When the acid value of the tackifier is larger than the above range, the adhesive strength is reduced, and when it is small, the compatibility with the copolymer is insufficient, and even when the compounding amount is more than the above range, the compatibility is low. On the contrary, there is a tendency that the effect is not recognized because the adhesive force is reduced even if the amount is small.

The tackifier (B4) may be any one which satisfies the above acid value, and includes rosin ester, hydrogenated rosin, polymerized rosin, rosin such as disproportionated rosin, terpene resin, petroleum resin and the like. For example, the acid value may be adjusted to the above range by introducing a carboxyl group or the like by a method such as modification with maleic acid. Above all, it is effective to use a rosin-based tackifier. The acrylic copolymer is easily produced by a method well known to those skilled in the art, such as radical copolymerization of the components (B1) to (B3) described above in an organic solvent.
Examples of the organic solvent used in the polymerization include aromatic hydrocarbons such as toluene and xylene, esters such as ethyl acetate and butyl acetate, aliphatic alcohols such as n-propyl alcohol and iso-propyl alcohol, methyl ethyl ketone and methyl. Examples thereof include ketones such as isobutyl ketone and cyclohexanone, and examples of the polymerization catalyst used in radical polymerization include azobisisobutyronitrile, benzoyl peroxide, di-t-butyl peroxide, which are ordinary radical polymerization catalysts, Specific examples include cumene hydroperoxide.

A pressure-sensitive adhesive composition (B) excellent in alkali solubility is obtained by blending and dissolving the above-mentioned tackifier (B4) in the acrylic copolymer obtained by such a method at a temperature of about 40 ° C. However, in order to make the composition soluble in ordinary water, it is possible to neutralize the composition with an alkali such as potassium hydroxide, sodium hydroxide or amine. Further, the composition can withstand practical use as a pressure-sensitive adhesive sufficiently as it is, but in order to further improve the adhesive performance, the composition of the composition is 0.
It is also possible to add 01 to 5 parts by weight of a cross-linking agent, and examples of the cross-linking agent include epoxy-based, isocyanate-based, metal chelate-based, amine-based, etc., and one or more of them are selected, preferably Is an epoxy type or a metal chelate type. In addition to the above-mentioned composition, the composition may be mixed with a colorant, a stabilizer, a filler, an adhesion improver and the like.

[0018] Such viscosity obtained by the method Chakuzai composition (B)
Any method may be adopted for laminating the layer comprising the biodegradable or photodegradable resin composition (A), but usually, the biodegradable or photodegradable resin composition (A) is used. known method such as a roll coater method to a layer made of, it is possible to obtain a laminated molded product of the present invention than applying lamination viscosity Chakuzai composition (B). (A) and (B) in the molded product
Is suitably selected from the range of 10 to 100 μ and 10 to 100 μ, respectively, preferably 25 to 60 μ and 10 to 40 μ, and the total thickness of (A) + (B) is 20 to
It is suitably selected from the range of 150 μ, preferably 30 to 100 μ.

The laminated molded article of the present invention is a variety of adhesives such as packaging adhesive tapes, office adhesive tapes, medical adhesive products, electrical insulating tapes, masking tapes or sheets, adhesive labels, double-sided adhesive tapes and special adhesive tapes. It can be used for processed products, but considering the biodegradability or photodegradability of the base material, adhesiveness with polyolefin resin, solubility in water and alkaline water, etc. It is very useful as an agricultural adhesive sheet and adhesive tape such as an adhesive label, an adhesive tape, a special adhesive tape, an adhesive sheet for raising seeds, and a grafting tape.

[0020]

SUMMARY OF laminated molding of the present invention, since the photodegradable and / or biodegradable resin composition layer and the tacky Chakuzai composition comprising (A) a layer consisting of (B) are laminated, various adhesive Adhesive labels for food / pharmaceutical containers, etc. that can be used for processed products, especially adhesive / tape tapes, special adhesive tapes, seed-adhesive sheets, grafting tapes and other agricultural adhesive sheets,
It is very useful as an adhesive tape because it is easy to dispose of and has little adverse effect on the environment.

[0021]

EXAMPLES The present invention will be specifically described below with reference to examples. In the examples, "parts" and "%" are based on weight unless otherwise specified. [Photodegradable and / or biodegradable resin composition (A)] The following resin compositions were prepared. A1; ethylene-carbon monoxide copolymer (copolymerization ratio of carbon monoxide: 1.6% by weight) A2: thermoplastic 1,2-polybutadiene A3; saponified ethylene-vinyl acetate copolymer (ethylene content 44 mol%, ken 45 parts of raw starch (corn starch having a water content of 12% by weight) 55
Part and a mixture of 20 parts of glycerin A4; a mixture of 80 parts of an ethylene-vinyl acetate copolymer saponified product (ethylene content 29 mol%, saponification degree 99.3 mol%) and 20 parts of polycaprolactone

[Water or alkali-soluble adhesive composition (B)] 40 parts by weight of 2-ethoxyethyl acrylate (2-EEA), 50 parts by weight of n-butyl acrylate (BA), 5 parts by weight of vinyl acetate (VAc) Part, acrylic acid (AAc) 5
Parts by weight, 60 parts by weight of ethyl acetate, 20 parts by weight of methanol, and 0.1 parts by weight of azobisisobutyronitrile (AIBN) were placed in a flask equipped with a condenser, a stirrer and a thermometer, and heated to 90 ° C to polymerize. During the polymerization, 10 parts by weight of toluene and 0.1 parts by weight of AIBN dissolved in the polymerization catalyst solution were successively added to carry out polymerization for 7 hours, and then the concentration was adjusted by adding toluene to obtain a glass transition temperature (Tg). −
Resin content 40% by weight of resin at 46 ° C, solvent content 60% (ethyl acetate / methanol / toluene = 6/2 /
(2 weight ratio) to obtain a resin composition. An acid value of 200 mg KOH as a tackifier based on 200 parts by weight of the resin composition
/ G, 20 parts by weight of maleic acid-modified rosin having a softening point of 105 ° C. (20 parts by weight with respect to 80 parts by weight of the resin content of the resin composition) is added to give the pressure-sensitive adhesive composition (B) of the present invention. Obtained. Further, according to the above method, pressure-sensitive adhesive compositions (B-1 to 6) having the composition shown in Table 1 were prepared.

[0023]

[Table 1] Acrylic Copolymer Tackifier (B4) (B1) Component (B2) Component (B3) Component Tg (° C) Type Acid Value (mgKOH / g) B-12-EEA AAc BA VAc-46 Rosin-1 200 (40) (5) (50) (5) (80/20) 〃 2 2-EEA AAc BA VAc-46 Rosin-1 200 (40) (5) (50) (5) (80 / 20) 〃 3 2-EEA AAC BA VAc-46 Rosin-2 150 (40) (5) (50) (5) (80/20) 〃 4 2-EEA AAc BA VAc-45 Terpene 200 (70) (5) ) (20) (5) (90/10) 〃 5 2-EEA AAc BA V Ac-46 No additive (40) (5) (50) (5) 〃 6 2-EEA AAc 2-EHA VAc -55 No additive (40) (5) (50) (5)

Note) Numbers in parentheses indicate parts by weight.
However, the term of the component (B4) represents a blending weight ratio with the acrylic copolymer (acrylic copolymer / tackifier).
Further, B-2,6 was made water-soluble by neutralizing it with sodium hydroxide. The abbreviations are as follows. 2-EEA; 2-ethoxyethyl acrylate, AAc; acrylic acid, BA; n-butyl acrylate, VAc; vinyl acetate, 2-EHA; 2-ethylhexyl acrylate rosin-1; maleic acid modified rosin (softening point 105 ° C.) Rosin-2: Hydrogenated modified rosin (softening point 80 ° C) Terpene: Maleic acid modified terpene phenol (softening point 115 ° C)

Example 1 The above decomposable resin composition (A1 to A7) was 40 μm in an extruder.
Of the sheet (A-1 to 7), and the pressure-sensitive adhesive composition (B-1 to 6) was applied to one surface of the sheet using a roll coater so that the dry thickness was 25 μm, and the results are shown in Table 2. An adhesive sheet (NO.1-9) was obtained. This adhesive sheet is attached to a stainless steel plate (SUS304), and the temperature is 20 ° C. and 65% RH.
The peel strength was measured according to JIS Z 0237 Adhesion Force Measurement Method. On the other hand, the pressure-sensitive adhesive sheet was attached to a glass container, completely immersed in a 3% NaOH aqueous solution at 20 ° C., and 60 minutes later, the peeled state of the sheet was visually observed.
Furthermore, the peeled sheet is exposed outdoors (in summer) for 2 months (NO.1,2,5,6) or buried in the soil of an industrial waste site for 6 months (NO.3,4,7,8, 9), the state of decomposition (disintegration) of the sheet was visually observed.

Comparative Example 1 The above-mentioned pressure-sensitive adhesive composition B-1 was applied to a PET (polyethylene terephthalate) film for labels (50 μm) in the same manner as in Example 1, and similarly peeled off and decomposed (disintegrated) after outdoor exposure. I checked the situation. Comparative Example 2 Normal acrylic pressure-sensitive adhesive composition (weight ratio n-butyl acrylate / methacrylate / acrylic acid = 80/17
/ 3 copolymer, B-7) to the above resin composition sheet A-
1 was applied in the same manner as in Example 1, and the peeling state and the state of decomposition (disintegration) after outdoor exposure were similarly examined. The results of Examples and Comparative Examples are also shown in Table 2.

[0027]

[Table 2] Resin composition Adhesive composition Peel strength Peeling state Decomposition (disintegration) status (g / inchi) Example 1 NO.1 A-1 B-1 1400 Complete drop-off The original shape was not stopped 〃 2 A-2 B -2 1500 〃 〃 3 A-3 B-3 1200 1200 〃 〃 〃 4 A-4 B-4 1450 〃 〃 〃 5 A-1 B-5 1000 〃 〃 〃 6 A-2 B-6 〃 1100 〃 7 A-3 B-1 1500 〃 〃 〃 8 A-4 B-2 1300 〃 〃 〃 9 A-3 B-6 1100 〃 Comparative Example 1 PET B-1 1200 〃 No decomposition 〃 2 A-1 B -7 1100 No peeling * Note) No. 2, 6, 8, and 9 of Example 1 were immersed in water to evaluate the peeling state. * After the adhesive sheet was peeled off by hand, it was exposed to the outdoors, but the adhesive remained.

Example 2 As a graft tape, the No. 2 pressure-sensitive adhesive sheet of Example 1 was used and wound around the graft portion and fixed. Adhesiveness was sufficient, and the grafted portion was steadily grown even after 2 months of outdoor exposure, the pressure-sensitive adhesive sheet was almost completely decomposed (disintegrated), and it was not necessary to remove the pressure-sensitive adhesive sheet. Comparative Example 3 In Example 2, a commercially available vinyl chloride pressure-sensitive adhesive tape was used and evaluated in the same manner as in Example 2. As a result, the adhesiveness was sufficient, but the adhesive tape was not decomposed even after 3 months of outdoor exposure. I was not able to admit.

[0029]

INDUSTRIAL APPLICABILITY The laminated molded article of the present invention is photodegradable and / or
Or biodegradable resin composition since the laminated layers of the layer and the viscosity Chakuzai composition comprising (A) (B), can be used in various adhesives workpiece, in particular reusable for Food, Drug Adhesive tapes such as containers, adhesive labels, special adhesive tapes or seed-growing adhesive sheets, agricultural adhesive sheets such as grafting tapes, etc. .

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 5-92507 (JP, A) JP 5-269932 (JP, A) JP 5-84874 (JP, A) JP 2- 107686 (JP, A) JP-A-7-81274 (JP, A) JP-A-57-90076 (JP, A) Actual development 5-75782 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G09F 3/00-3/10 B32B 9/00 B32B 27/30

Claims (6)

(57) [Claims] 1. A layer composed of a photodegradable and / or biodegradable resin composition (A) and a (meth) acrole having an ether bond.
Relate ( B1 ) 30 to 98% by weight, α, β-unsaturated cal
2 to 20% by weight of boric acid or a salt thereof ( B2 ) and the above monomer
From 0 to 68% by weight of monomer ( B3 ) copolymerizable with
Glass transition temperature (Tg) of -20 ° C or lower
A laminate formed by laminating layers comprising the pressure-sensitive adhesive composition (B). 2. A photodegradable and / or biodegradable resin composition
(A) Layer- containing (meth) acrylate having an ether bond (B1) 30 to 98% by weight, α, β-unsaturated carboxylic acid or its salt (B2) 2 to 20% by weight and copolymerizable with the above monomers Of glass transition temperature (Tg) -20 ° C or less consisting of 0 to 68% by weight of simple monomer (B3)
(B) 95-60 parts by weight and an acid value of 100-300 mgK
Contains 5 to 40 parts by weight of OH / g tackifier ( B4 )
A laminated molded article, which is obtained by laminating layers composed of the pressure-sensitive adhesive composition (B) . 3. A biodegradable resin composition (A) is, according to claim 1 or 2 laminated molded article wherein a formed of thermoplastic resin and starch polymers. 4. The adhesive sheet laminated molded article according to any one of claims 1-3, characterized by using a tape or label. 5. The laminated molded article according to claim 4 , which is used for a container for food or medicine. 6. The laminated molded product according to claim 4 , which is used as an agricultural material.