KR101174668B1 - Adhesive Composition and Manufacturing Method thereof - Google Patents

Abstract

The invention (a) (meth) acrylate monomer having an alkyl group of C1 ~ C14; Polymerizing the (meth) acrylate monomer having a hydroxy group, the (meth) acrylate monomer having a carboxyl group, or a mixture thereof; It relates to a pressure-sensitive adhesive composition prepared from a method for producing a pressure-sensitive adhesive composition comprising a and b) a step of grafting (addition reaction) polymerization of alkylglycidyl ether of C8 ~ C12 to the polymer. The pressure-sensitive adhesive composition according to the present invention is excellent in wettability and re-peelability.

Description

Adhesive composition and manufacturing method thereof

The present invention relates to a method for preparing the pressure-sensitive adhesive composition, and more particularly, to a pressure-sensitive adhesive composition and a method for producing the same, which have excellent wettability and maintain re-peelability and are stable in late adhesion.

The pressure-sensitive adhesive composition having excellent wettability, re-peelability, and low change over time is widely used in general industrial fields in special labels or tapes, adhesive sheets for surface protection and adhesive tapes for masking, and tapes for wafer manufacturing processes. The wettability refers to the property of wetting immediately after adhesion due to the surface energy and adhesive properties of the adhesive. The re-peelability refers to the property of falling off from the adherend without leaving residue after being adhered to the adherend by the adhesiveness of the adhesive.

However, in the adhesive, the wettability and the adhesiveness are correlated with each other, and the adhesion maintained by the adhesiveness and the wettability is stable even over time. The property of excellent adhesiveness and the property of excellent peeling property are opposite to each other. If the adhesive property is excellent, the re-peelability is lowered, and if the re-peelability is increased, there is a problem that the adhesiveness is lowered.

That is, when the glass transition temperature of the adhesive is lowered to enhance the adhesiveness, the flowability of the adhesive is improved, the penetration of the adherend can be easily penetrated into the surface of the adherend, but the adhesiveness is high. However, the crosslinking density is low and the re-peelability is reduced due to the surface migration of the low molecular weight material. Degradation and use of a high adhesive function had a severe problem over time.

Korean Patent Laid-Open Publication No. 10-2009-0111286 discloses an adhesive film exhibiting excellent water resistance and excellent peeling properties, re-peelability, and wettability to a wafer, and a backgrinding method using the same. In addition, Korean Patent Laid-Open Publication No. 2006-0047526 discloses a pressure-sensitive adhesive film for protecting a semiconductor wafer having a limited storage modulus at a specific temperature as being capable of preventing damage even when the thickness of the semiconductor wafer is reduced. In the case of the pressure-sensitive adhesive film proposed in the above-mentioned prior art, it satisfies the properties of initial adhesion and re-peelability, but causes a problem of change in adhesive force over time and residues after time of attachment, and in the adhesive for semiconductor process, wafers at the time of back grinding The breakage prevention effect of the can be obtained to some extent, but if the work process is not made immediately, the adhesive force increases due to the interaction between the adhesive and the adhesive, resulting in the residue remaining due to the increase in the adhesive force. In addition, there is a problem that the cutting property is significantly poor when cutting the wafer in the process. In this way, an increase in the adhesive force in the wafer process leads to a wafer defect due to the defect of the adhesive, which lowers the efficiency of many processes. If the cutability of the protective film is poor, the semiconductor processing process may be discontinuously performed due to the problem of poor cutting of the film during the semiconductor processing process performed in the in-line process, thereby reducing the efficiency of the process. Will be.

Therefore, various methods of preparing a pressure-sensitive adhesive composition to improve the wettability to maintain adhesiveness and harmonize re-peelability have been studied.

In order to solve the above problems, the present invention has excellent wettability, and thus the adhesive strength is kept constant at the time of initial attachment, and a method of preparing an adhesive composition having excellent adhesion and re-peelability without leaving residue on the adherend even after time of attachment The purpose is to provide. Moreover, an object of this invention is to provide the adhesive composition manufactured from the said manufacturing method.

In order to achieve the above object, the inventors

a) (meth) acrylate type monomer which has C1-C14 alkyl group; Polymerizing the (meth) acrylate monomer having a hydroxy group, the (meth) acrylate monomer having a carboxyl group, or a mixture thereof; And

b) graft (addition reaction) polymerization of C8-C12 alkylglycidyl ether into the polymer; It provides a method for producing a pressure-sensitive adhesive composition comprising a.

In addition, the present invention provides a pressure-sensitive adhesive composition prepared by the above production method.

Hereinafter, the present invention will be described in detail.

The present invention is a (meth) acrylate monomer having an alkyl group of C1 ~ C14; And a (meth) acrylate monomer having a hydroxy group, a (meth) acrylate monomer having a carboxyl group, or a mixture thereof.

The (meth) acrylate-based monomer having an alkyl group of C1 to C14 is a monomer that provides adhesion, and more preferably a glass transition temperature of -70 to 130 ° C, preferably an alkyl group of C4 to C14. If the carbon number is out of the above range is not preferable because the glass transition temperature is high or the control of the stickiness is difficult.

The polymer contains 70 to 90% by weight of a (meth) acrylate monomer having an alkyl group of C1 to C14. When the content of the acrylate monomer is less than 70% by weight, the adhesiveness decreases and thus it may not exhibit physical properties as the pressure-sensitive adhesive. When the content of the acrylate monomer exceeds 90% by weight, the pressure-sensitive adhesive flows so large that the adhesive area becomes wider and re-peelable. Degrades.

 The (meth) acrylate-based monomer having an alkyl group of C1 ~ C14 is methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethyl butyl acrylate, 2-ethylhexyl acrylate, hexyl acrylate, heptyl acrylate, Octyl acrylate, n-pentyl acrylate, vinyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylbutyl methacrylate, 2-ethylhexyl methacrylate or And lauryl methacrylate. These monomers may be used alone or in combination of two or more thereof.

The polymer includes 10 to 30% by weight of a (meth) acrylate monomer having a hydroxy group, a (meth) acrylate monomer having a carboxyl group or a mixture thereof. The content of alkylglycidyl ether of C8 ~ C12 is determined according to their contents. When the above range is less than 10% by weight, the cohesion is low and the re-peelability is lowered. When the content exceeds 30% by weight, the crosslinking degree is increased, resulting in weak adhesion and wettability. There is a problem that the re-peelability is lowered.

The (meth) acrylate-based monomer having hydroxy is 2-hydroxyethyl acrylate, 2-hydroxymethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxy Ethyl methacrylate, 2-hydroxymethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate; The (meth) acrylate-based monomer having a carboxyl group includes maleic acid, itaconic acid, acrylic acid, or methacrylic acid, and these monomers may be used alone or in combination of two or more thereof. More preferably, a (meth) acrylate monomer having a carboxyl group is preferable. The monomer having a carboxyl group has a functional impartment and a crosslinking functional group at the time of synthesizing the pressure-sensitive adhesive, which is very useful and responsive at the time of synthesis through molecular design of the pressure-sensitive adhesive. In addition, the high polarity of the carboxyl group is easy to control the adhesion and physical properties through interaction with the adherend, and excellent reactivity in addition reactions with other heterogeneous monomers and substances and chemical bonding with various functional groups.

In addition, the polymer may further copolymerize by including an initiator.

The copolymerization method includes a solution polymerization method, a photopolymerization method, a bulk polymerization method, a suspension polymerization method or an emulsion polymerization method, and the solution polymerization method is most preferred. At this time, the polymerization temperature is preferably 6 hours to 12 hours at 50 ~ 140 ℃, it is preferable to add the initiator after mixing the monomers uniformly.

The initiator may be a photoinitiator of 4- (2-hydroxyethoxyphenyl); Azo polymerization initiators, such as 2,2'- azobisisobutyronitrile, 2,2'- azobis (2-methylbutyronitrile), and 1,1'- azobis (cyclohexane-1-carbonitrile) , thermal polymerization initiators of organic peroxides such as tert-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, inorganic peroxides such as potassium persulfate and hydrogen peroxide; but are not necessarily limited thereto.

The invention (a) (meth) acrylate monomer having an alkyl group of C1 ~ C14; A (meth) acrylate monomer having a hydroxy group, a (meth) acrylate monomer having a carboxyl group or a mixture thereof; and polymerizing the resulting polymer by adding C8-C12 alkylglycidyl ether to a graft (addition reaction). ) Polymerization.

The alkylglycidyl ether of C8 to C12 is added 0.1 to 1 mol relative to the functional group of the (meth) acrylate monomer having a hydroxy, a (meth) acrylate monomer having a carboxyl group or a mixture thereof. If the content is less than 0.1 mol, the wettability and adhesion decreases large, and if it exceeds 1 mol, the cohesive strength of the polymer decreases due to the lack of a crosslinking point, the late gradual force rises, and residues remain in the adherend, and re-peelability is not easy. And an increase in adhesive force due to heat.

The alkylglycidyl ethers of C8 to C12 include laurylglycidyl ether, octylglycidyl ether, undecylglycidyl ether, and the like. These alkylglycidyl ethers may be used alone or in combination of two or more thereof. .

By adding the alkylglycidyl ethers of C8 to C12, the carbon-carbon side chain having a soft structure is lengthened, thereby increasing the fluidity of the pressure-sensitive adhesive. Therefore, the pressure-sensitive adhesive is better wetted on the adhered surface, thereby increasing the adhesive force.

The present invention further comprises 0.1 to 5 parts by weight of a crosslinking agent based on 100 parts by weight of the pressure-sensitive adhesive composition. If the content of the crosslinking agent is less than 0.1 part by weight, the crosslinking reaction may not proceed smoothly, and the cohesion force of the pressure-sensitive adhesive may be lowered. If the content of the crosslinking agent is more than 5 parts by weight, the crosslinking reaction may proceed excessively, and thus the durability may be lowered.

The crosslinking agent includes an isocyanate compound, an epoxy compound, an aziridine compound or a metal chelate compound, and more preferably an epoxy compound. Examples of the epoxy compound include ethylene glycol diglycidyl ether, triglycidyl ether, trimethol propane triglycidyl ether, N, N, N ', N'-tetraglycidyl ethylenediamine or glycerin diglycidyl ether. Etc., but is not necessarily limited thereto.

Moreover, this invention is a) (meth) acrylate type monomer which has a C1-C14 alkyl group; And b) a (meth) acrylate monomer having a hydroxy group or a carboxyl group; It provides a pressure-sensitive adhesive composition prepared by grafting (adding) C8-C12 alkylglycidyl ether to a polymer of.

In addition, the adhesive composition of the present invention provides an adhesive composition having a hydroxyl value of 30 to 130 or an acid value of 5 to 80.

In addition, UV stabilizers, antioxidants, pigments, dyes, reinforcing agents, fillers and the like may be appropriately added and used in the pressure-sensitive adhesive composition according to the general purpose without affecting the effects of the invention.

In addition, the pressure-sensitive adhesive composition of the present invention may provide a pressure-sensitive adhesive film having a uniform pressure-sensitive adhesive layer of 5 ~ 30㎛ after drying by coating on one surface of a polyolefin-based, polyethylene terephthalate, polyethylene or polypropylene film.

The pressure-sensitive adhesive composition prepared by the manufacturing method according to the present invention has excellent wettability, and thus the adhesive strength is kept constant at the time of initial attachment, and excellent adhesion and re-peelability without leaving bubbles or residue on the adherend even after time of attachment It works.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not intended to limit the scope of the present invention.

[Examples 1-5]

Preparation of pressure-sensitive adhesive composition

Nitrogen gas is filled, and a thermometer and a cooling device are installed inside and outside to facilitate temperature control, and the (meth) acrylate monomer in the composition of Table 1 in a 2 L reactor that can control the reaction rate and heat generation of the reactants. (Meth) acrylate monomers having a hydroxy or carboxyl group were added thereto. To 100 parts by weight of the mixture composed of the monomers shown in Table 1, 30 parts by weight of toluene and 70 parts by weight of ethylacetate (ethylacetate, EAc) were added.

Then, after purging nitrogen gas for 20 minutes to remove oxygen, and stirring the monomer mixture uniformly, 0.06 parts by weight of azobisisobutyronitrile (AIBN) as a reaction initiator for 10 hours. 1.6 parts by weight was added. The polymer was prepared by maintaining the temperature of the reactor at 90 ° C. and reacting for 10 hours while adding a small amount of the reactant dropwise. Alkyl glycidyl ether was reacted with the polymer at the composition of Table 1 at 80 ° C. for 10 hours to prepare Examples 1 to 5.

Comparative Example 1

It was prepared in the same manner as in Examples 1 to 5 except that no alkylglycidyl ether was added.

Comparative Example 2

It was prepared in the same manner as in Examples 1 to 5, except that 5 mol of lauryl glycidyl ether was added.

Comparative Example 3

It was prepared in the same manner as in Examples 1 to 5, except that 10 mol of lauryl glycidyl ether was added.

[Table 1]

week)

BA: Butyl acrylate

2-EHA: 2-ethylhexyl acrylate

2-EHMA: 2-ethylhexyl methacrylate

AA: acrylic acid

MA: methacrylic acid

2-HEMA: 2-hydroxyethyl methacrylate

2-HEA: 2-hydroxyethylacrylate

LGE: lauryl glycidyl ether (molar ratio compared to 2-HEMA, 2-HEA, AA, MA >>)

OGE: octyl glycidyl ether (molar ratio compared to AA, MA >>)

Preparation of Adhesive Film

2.0 parts by weight of (trade name Tetra-DX: manufactured by Japan) as a crosslinking agent was added to the prepared Examples 1 to 5 and Comparative Examples 1 to 3, and mixed uniformly, and then a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm. After coating and drying one surface of (SKC Hass) to prepare a pressure-sensitive adhesive film having a uniform pressure-sensitive adhesive layer of 20㎛ and evaluated the physical properties as shown in Table 2 below.

(1) adhesion test

The release film was laminated to the prepared pressure-sensitive adhesive film, and stored at a temperature of 43 ° C. for 3 days to mature, and then attached to glass to test adhesion. The film was attached to the glass surface with a roller of 2 kg according to JIS Z 0.27, and then stored at 25 ° C. and 50% relative humidity for 24 hours, followed by 180 ° angle and 300 mm / min peeling. Rate was measured using a tensile tester Texture Analyzer (manufacturer: Stable Micro Systems).

(2) wetting properties

The prepared pressure-sensitive adhesive film was cut into silicon wafers in a size of 2.54 cm and 10 cm, respectively, to prepare a sample, and after peeling off the protective film, measuring the time when the protective film completely wets the glass surface without applying external pressure. And evaluated according to the following criteria. (○: less than 10 seconds, Δ: 10 seconds or more, less than 30 seconds, ×: 30 seconds or more)

(3) increased adhesion with time

In order to measure the adhesive strength over time, after the adhesive film is adhered to the glass surface, the adhesive strength of 20 minutes was measured, and after 24 minutes, the adhesive strength after 24 hours and the adhesive strength after 7 days were measured. The rate of increase was expressed in%.

(4) Residue of appearance after peeling (adhesive, ie residue on wafer surface)

After the adhesion test, the degree of contamination, appearance, peel strength, and the like of the silicon surface on which the film was peeled off were comprehensively evaluated.

(Good: easily peelable, no residue of adhesive on glass substrate, poor: adhesive residue on glass substrate)

(5) hydroxy value measurement

The hydroxyl number is a measure of the amount of residual -OH functional groups and measures the number of hydroxyl groups present that can be acetylated. The hydroxyl value (or acetyl value) is defined as the number of milligrams of KOH required to neutralize acetic acid (produced) in acetylation of 1 g of sample.

(6) Acid value measurement

The acid value is a measure of the amount of functional groups of residual -COOH, and the acid value is the number of mg of KOH required to neutralize the acid contained in 1 g of the sample.

(A = Consumption of 0.1N KOH solution used for titration (ml)

F = Factor of correction of KOH solution

M = weight of sample)

[Table 2]

As shown in Table 2, in the case of Examples 1 to 5 to which 0.5 to 1.0 mol of alkylglycidyl ether was added, it was confirmed that the wettability and the adhesive force were stabilized.

On the other hand, in the case of Comparative Example 1 without the alkyl glycidyl ether it can be seen that the wettability is poor, the adhesive strength is relatively high, the re-peelability is relatively low, it was confirmed that the surface contamination during peeling is severe. In addition, when the alkylglycidyl ether is added in an excessive amount as in Comparative Examples 2 to 3, the wettability is good, but the late adhesive strength is increased compared to the initial adhesive strength, and thus re-peelability and ease of reworking are inferior.

Claims (11)

a) 70 to 90% by weight of a (meth) acrylate monomer having an alkyl group of C1 to C14; 10 to 30% by weight of a (meth) acrylate monomer having a hydroxy group, a (meth) acrylate monomer having a carboxyl group or a mixture thereof; And
b) C8-C12 alkylglycidyl ether is added to the polymer at 0.1 to 1 mol relative to the functional group of the (meth) acrylate monomer having a hydroxy group, the (meth) acrylate monomer having a carboxyl group, or a mixture thereof. Graft (addition reaction) polymerization;
Method of producing a pressure-sensitive adhesive composition comprising a. delete delete delete The method of claim 1,
The (meth) acrylate-based monomer having an alkyl group of C1 ~ C14 is methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethyl butyl acrylate, 2-ethylhexyl acrylate, hexyl acrylate, heptyl acrylate, Octyl acrylate, n-pentyl acrylate, vinyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylbutyl methacrylate, 2-ethylhexyl methacrylate or A method for producing a pressure-sensitive adhesive composition which is at least one mixture selected from the group consisting of lauryl methacrylate. The method of claim 1,
The (meth) acrylate-based monomer having hydroxy is 2-hydroxyethyl acrylate, 2-hydroxymethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxy Ethyl methacrylate, 2-hydroxymethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate; The (meth) acrylate-based monomer having a carboxyl group is a pressure-sensitive adhesive composition manufacturing method of at least one mixture selected from the group consisting of maleic acid, itaconic acid, acrylic acid or methacrylic acid. The method of claim 1,
The C8-C12 alkyl glycidyl ether is at least one selected from the group consisting of lauryl glycidyl ether, octyl glycidyl ether or undecyl glycidyl ether. The method of claim 1,
The pressure-sensitive adhesive composition further comprises 0.1 to 5 parts by weight of a crosslinking agent based on 100 parts by weight of the polymer. The method of claim 8,
The crosslinking agent is at least one selected from the group consisting of an isocyanate compound, an epoxy compound, an aziridine compound or a metal chelate compound. Alkyl glycidyl ether of C8-C12 to the polymer of 70 to 90% by weight of the acrylate monomer having a C1 to C14 alkyl group and 10 to 30% by weight of the (meth) acrylate monomer having a hydroxy group or a carboxyl group is added to the hydroxy group. A pressure-sensitive adhesive composition prepared by graft polymerization by adding 0.1 to 1 mol of a (meth) acrylate monomer having a carboxyl group, a (meth) acrylate monomer having a carboxyl group, or a mixture thereof. The method of claim 10,
Said adhesive composition is an adhesive composition whose hydroxy value is 30-130 or an acid value is 5-80.